HV9912NG-G [MICROCHIP]
LED DISPLAY DRIVER, PDSO16;
| 型号： | HV9912NG-G |
| 厂家： | 
MICROCHIP |
| 描述： | LED DISPLAY DRIVER, PDSO16 驱动 光电二极管 接口集成电路 |
| 文件： | 总20页 (文件大小：724K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
HV9912
Switch-Mode LED Driver IC with High Current Accuracy
and Hiccup Mode Protection
Features
General Description
• Switch-mode Controller for Single-switch Drivers:
HV9912 is an LED driver IC designed to control
single-switch PWM converters (buck, boost,
buck-boost and SEPIC) in a Constant Frequency or
Constant Off-time mode. The controller uses a peak
Current Mode control scheme with programmable
slope compensation and includes an internal
transconductance amplifier to control the output current
in closed loop, enabling high output current accuracy.
In the case of buck and buck-boost converters, the
output current can be sensed using a high-side current
sensor like the HV7800. In the Constant Frequency
mode, multiple HV9912 ICs can be synchronized with
each other or with an external clock, using the SYNC
pin. Programmable MOSFET current limit enables
current limiting during Input Undervoltage and Output
Overload conditions. The IC also includes a 0.2A
source and 0.4A sink gate driver that makes the
HV9912 suitable for high-power applications. An
internal 90V linear regulator powers the IC, eliminating
the need for a separate power supply for the IC. The IC
also provides a FAULT output, which can be used to
disconnect the LEDs in case of a Fault condition using
an external disconnect FET. HV9912 also provides a
TTL-compatible, low-frequency PWM dimming input
that can accept an external control signal with a duty
ratio of 0-100% and a frequency of up to a few kilohertz.
The HV9912 includes hiccup protection from both short
and open circuits, with automatic recovery after the
Fault condition is cleared.
- Buck
- Boost
- Buck-boost
- SEPIC
• Works with High-side Current Sensors
• Closed-loop Control of Output Current
• High Pulse-Width Modulation (PWM) Dimming
Ratio
• Internal 90V Linear Regulator (can be extended
using external Zener Diodes)
• Internal 2% Voltage Reference (0°C < TA < 85°C)
• Constant Frequency or Constant Off-time
Operation
• Programmable Slope Compensation
• Linear and PWM Dimming
• +0.2A/–0.4A Gate Driver
• Hiccup Mode Protection for both Short-circuit and
Open-circuit Conditions
• Output Overvoltage Protection
• Synchronization Capability
• Pin Compatible with HV9911
Applications
• RGB Backlight Applications
• General LED Lighting Applications
• Battery-powered LED Lamps
The HV9912 is a pin-compatible replacement for
HV9911. It can be used with existing HV9911 designs,
which have input voltages of less than 90V, by
changing ROVP1, ROVP, and RT.
Package Type
16-lead SOIC
(Top View)
1
2
3
4
5
6
7
8
16
VIN
VDD
GATE
GND
CS
FDBK
IREF
15
14
13
12
11
10
9
COMP
PWMD
OVP
SC
FAULT
REF
RT
See Table 2-1 for pin information.
SYNC
CLIM
2016 Microchip Technology Inc.
DS20005583A-page 1
HV9912
Functional Block Diagram
VIN
Linear Regulator
Vbg
REF
VDD
+
SS
-
5.60/6.10V
CLIM
CS
-
+
POR
GATE
Blanking
TBLANK
+
-
Q
1:2
R
S
ramp
+
-
FAULT
OVP
SS
5V rising
4.5V falling
SC
POR OVD SCD
-
OVPD
13R
+
Hiccup/Dimming
Block
COMP
R
TBLANK,SC
+
-
PWMD
SS
SCD
SYNC
RT
FDBK
IREF
-
GM
One Shot
+
2
PWMD
GND
PWMD
DS20005583A-page 2
2016 Microchip Technology Inc.
HV9912
Typical Application Circuit
L1
D1
ROVP1
D2
VIN
Q1
CIN
VIN
1
GATE
CS
3
5
CO
CDD
RSC
ROVP2
RCS
2
4
VDD
GND
12
11
16
14
13
8
OVP
HV9912
RSLOPE
RT
6
7
SC
FAULT
FDBK
COMP
PWMD
SYNC
Q2
RT
CC
CREF
RS
REF
10
9
CLIM
IREF
RL1
RR1
15
RL2
RR2
2016 Microchip Technology Inc.
DS20005583A-page 3
HV9912
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
VIN to GND ............................................................................................................................................... –0.5 to +100V
VDD to GND............................................................................................................................................–0.3V to +13.5V
CS to GND ........................................................................................................................................ –0.3V to VDD+0.3V
PWMD to GND.................................................................................................................................. –0.3V to VDD+0.3V
GATE to GND.................................................................................................................................... –0.3V to VDD+0.3V
All Other Pins to GND ....................................................................................................................... –0.3V to VDD+0.3V
Continuous Power Dissipation (TA= +25°C)..................................................................................................... 1200 mW
Operating Junction Temperature Range .............................................................................................. –40°C to +125°C
Storage Temperature Range................................................................................................................ –65°C to +150°C
† Notice: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only, and functional operation of the device at those or any other conditions above those
indicated in the operational sections of this specification is not intended. Exposure to maximum rating conditions for
extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
Electrical Specifications: TA = 25°C and VIN = 12V unless otherwise specified.
Parameters
Sym.
Min.
Typ. Max. Units
Conditions
INPUT
Input DC Supply Voltage Range
Shutdown Mode Supply Current
INTERNAL REGULATOR
VINDC
IINSD
Note 1
—
—
90
V
DC input voltage (Note 2)
PWMD connected to GND
(Note 2)
—
1.5
mA
VIN = 9V–90V; PWMD con-
nected to GND (Note 2)
Internally Regulated Voltage
VDD
7.25
6.5
—
7.75 8.25
V
V
VDD Undervoltage Lockout
Threshold
UVLORISE
UVLOHYST
—
7
VDD rising
VDD falling
VDD Undervoltage Lockout
Hysteresis
500
—
mV
REFERENCE
REF bypassed with a 0.1 µF
capacitor to GND; IREF = 0;
PWMD = GND;
1.225 1.25 1.285
1.225 1.25 1.29
REF Pin Voltage
VREF
V
0°C < TA < +85°C
REF bypassed with a 0.1 µF
capacitor to GND; IREF = 0;
PWMD = GND;
–40°C < TA < 125°C
REF bypassed with a 0.1 µF
capacitor to GND; IREF = 0;
VDD = 7.25V–12V;
Line Regulation of Reference Voltage
VREFLINE
0
—
20
mV
PWMD = GND
Note 1: See Section 3.3 “Minimum Input Voltage at VIN Pin” for the minimum input voltage.
2: The specifications which apply over the full operating temperature range at
–40°C < TA < +85°C are guaranteed by design and characterization.
3: For design guidance only
DS20005583A-page 4
2016 Microchip Technology Inc.
HV9912
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: TA = 25°C and VIN = 12V unless otherwise specified.
Parameters
Sym.
Min.
Typ. Max. Units
Conditions
REF bypassed with a 0.1 µF
capacitor to GND;
IREF = 0 µA–500 µA;
PWMD = GND
Load Regulation of Reference
Voltage
VREFLOAD
0
—
10
mV
PWM DIMMING
PWMD Input Low Voltage
PWMD Input High Voltage
PWMD Pull-down Resistance
GATE
VPWMD(LO)
VPWMD(HI)
RPWMD
—
2
—
—
0.8
—
V
V
Note 2
Note 2
50
100
150
kΩ
VPWMD = 5V
GATE Short-circuit Current
GATE Sinking Current
GATE Output Rise Time
GATE Output Fall Time
OVERVOLTAGE PROTECTION
Overvoltage Rising Trip Point
Overvoltage Hysteresis
CURRENT SENSE
ISOURCE
ISINK
TRISE
TFALL
0.2
0.4
—
—
—
50
25
—
—
85
45
A
A
VGATE = 0V
VGATE = VDD
CGATE = 1 nF
CGATE = 1 nF
ns
ns
—
VOVP,RISING 4.75
5
5.25
—
V
V
OVP rising
OVP falling
VOVP,HYST
—
0.5
100
100
—
—
280
330
0°C < TA < +85°C
Leading Edge Blanking
TBLANK
ns
ns
–40°C < TA < +125°C
COMP = VDD; CLIM = REF;
CSENSE = 0 mV to 600 mV
(step up)
Delay to Output of COMP Comparator
TDELAY1
—
—
200
COMP = VDD; CLIM = 300 mV;
CSENSE = 0 mV to 400 mV
(step up)
Delay to Output of CLIMIT Comparator
Comparator Offset Voltage
TDELAY2
VOFFSET
—
—
—
200
10
ns
–10
mV
INTERNAL TRANSCONDUCTANCE OPAMP
75 pF capacitance at OP pin
(Note 3)
Gain Bandwidth Product
GBW
—
1
—
MHz
Open-loop DC Gain
Input Common Mode Range
Output Voltage Range
Transconductance
Input Offset Voltage
Input Bias Current
AV
VCM
60
–0.3
0.7
450
–5
—
—
—
3
dB
V
Output open
Note 3
VO
—
6.75
650
5
V
Note 3
gM
550
—
µA/V
mV
nA
VOFFSET
IBIAS
—
0.5
1
Note 3
OSCILLATOR
fOSC1
fOSC2
DMAX
99
510
87
106
580
—
118
650
93
kHz RT = 500 kΩ (Note 2)
kHz RT = 96 kΩ (Note 2)
%
Oscillator Frequency
Maximum Duty Cycle
Note 1: See Section 3.3 “Minimum Input Voltage at VIN Pin” for the minimum input voltage.
2: The specifications which apply over the full operating temperature range at
–40°C < TA < +85°C are guaranteed by design and characterization.
3: For design guidance only
2016 Microchip Technology Inc.
DS20005583A-page 5
HV9912
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: TA = 25°C and VIN = 12V unless otherwise specified.
Parameters
SYNC Input High
Sym.
Min.
Typ. Max. Units
Conditions
VSYNCH
VSYNCL
2
—
—
18
—
0.8
—
V
V
SYNC Input Low
—
—
SYNC Output Current
IOUTSYNC
µA
OUTPUT SHORT-CIRCUIT
Gain for Short-circuit Comparator
GSC
1.9
2
2.1
V
V
0°C < TA < +85°C;
IREF = GND
0.125
—
0.25
Minimum Output Voltage of the Gain
Stage
VOMIN
–40°C < TA < +125°C;
IREF = GND
0.125
—
—
—
0.26
250
PWMD = VDD; IREF = 400 mA;
FDBK step from
0 mV to 900 mV; FAULT goes
from high to low
Propagation Time for Short-circuit
TOFF
ns
Detection
Fault Output Rise Time
Fault Output Fall Time
Blanking Time
TRISE,FAULT
TFALL,FAULT
TBLANK,SC
—
—
—
—
—
300
300
900
ns
ns
ns
330 pF capacitor at FAULT pin
330 pF capacitor at FAULT pin
480
Current Source at COMP Pin used for
Hiccup Mode Protection
IHICCUP
—
5
—
µA
SLOPE COMPENSATION
Current Sourced Out of SC Pin
ISLOPE
0
—
2
100
µA
Note 2
I
SLOPE = 50 µA;
Internal Current Mirror Ratio
GSLOPE
1.8
2.26
RSC = 1 kΩ
Note 1: See Section 3.3 “Minimum Input Voltage at VIN Pin” for the minimum input voltage.
2: The specifications which apply over the full operating temperature range at
–40°C < TA < +85°C are guaranteed by design and characterization.
3: For design guidance only
TEMPERATURE SPECIFICATIONS
Parameters
Sym.
Min.
Typ.
Max.
Units
Conditions
TEMPERATURE RANGES
Operating Junction Temperature
Storage Temperature
TJ
Ts
–40
–65
—
—
+125
+150
°C
°C
PACKAGE THERMAL RESISTANCE
16-lead SOIC
JA
—
83
—
°C/W
DS20005583A-page 6
2016 Microchip Technology Inc.
HV9912
2.0
PIN DESCRIPTION
Table 2-1 shows the pin description details of HV9912.
TABLE 2-1:
Pin Number
1
PIN DESCRIPTION TABLE
Name
Description
VIN
VDD
GATE
GND
This pin is the input of a 90V high-voltage regulator.
This is a power supply pin for all internal circuits. It must be bypassed with a
low-ESR capacitor to GND (at least 0.1 µF).
2
3
4
This pin is the output gate driver for an external N-channel power MOSFET.
This is the ground return for all the low-power analog internal circuitry. This pin must
be connected to the return path from the input.
This pin is used to sense the source current of the external power FET. It includes a
built-in 100 ns (minimum) blanking time.
5
6
7
CS
SC
RT
This pin is used to set the slope compensation.
This pin sets the frequency of the power circuit. A resistor between RT and GND will
program the circuit in Constant Frequency mode.
This I/O pin may be connected to the SYNC pin of other HV9912 circuits and will
cause the oscillators to lock to the highest frequency oscillator.
8
9
SYNC
CLIM
REF
This pin provides a programmable input current limit for the converter. The current
limit can be set using a resistor divider from the REF pin.
This pin provides 2% accurate reference voltage. It must be bypassed with a
0.01 μF–0.1 μF capacitor to GND.
10
This pin is pulled to ground when there is an Output Short-circuit condition or Output
Overvoltage condition. This pin can be used to drive an external MOSFET (in the
case of boost converters) to disconnect the load from the source.
11
12
FAULT
OVP
This pin provides the overvoltage protection for the converter. When the voltage at
this pin exceeds 5V, the GATE output of the HV9912 is turned off, and the FAULT
goes low. The IC will turn on when the voltage at the pin goes below 4.5V.
When this pin is pulled to GND (or left open), switching of the HV9912 is disabled.
When an external TTL high level is applied to it, switching will resume.
13
14
15
16
PWMD
COMP
IREF
Stable Closed-loop control can be accomplished by connecting a compensation net-
work between COMP and GND. This capacitor also controls the hiccup time.
The voltage at this pin sets the output current level. The current reference can be set
using a resistor divider from the REF pin.
This pin provides output current feedback to the HV9912 by using a current sense
resistor.
FDBK
2016 Microchip Technology Inc.
DS20005583A-page 7
HV9912
3.3
Minimum Input Voltage at VIN Pin
3.0
3.1
DETAILED DESCRIPTION
The minimum input voltage at which the converter will
start and stop depends on the minimum voltage drop
required for the linear regulator. The internal linear
regulator will control the voltage at the VDD pin when
VIN is between 9V and 90V. However, when VIN is less
than 9V, the converter will still function as long as VDD
is greater than the undervoltage lockout. Thus, the
converter might be able to start at input voltages lower
than 9V. The start/stop voltages at the VIN pin can be
determined using the minimum voltage drop across the
linear regulator as a function of the current drawn. This
data is shown in Figure 3-1 for ambient temperatures of
25°C and 85°C.
Power Topology
The HV9912 is a Switch-mode converter LED driver
designed to control a Continuous Conduction mode
buck or boost in a Constant Frequency or Constant
Off-time mode. The IC includes an internal linear
regulator, which operates from input voltages up to
90V, eliminating the need for an external power supply
for the IC. The IC includes features typically required in
LED drivers, such as open LED protection, output
short-circuit protection, linear and PWM dimming,
programmable input current limiting and accurate
control of the LED current. A high-current gate drive
output enables the controller to be used in high-power
converters.
Assume an ambient temperature of 85°C. Provided
that the IC is driving a 15 nC gate charge FET at
200 kHz, the total input current is estimated to be
4.5 mA when Equation 3-1 is used. At this input
current, the minimum voltage drop from Figure 3-1
would be around VDROP = 1.25V. However, before the
IC starts switching, the current drawn would have been
1.5 mA. At this current level, the voltage drop would be
approximately VDROP1 = 0.3V. Thus, the start/stop VIN
voltages could be computed as demonstrated in
Equation 3-2 and Equation 3-3 below:
The HV9912 is an enhanced version of the HV9911
with hysteretic overvoltage protection and Hiccup
mode short-circuit protection. The IC includes a
blanking network controlled by the PWMD input to
prevent the short-circuit protection from triggering
prematurely during PWM dimming due to the parasitic
capacitance of the LED string. It also allows the IREF
pin to be pulled all the way down to GND without
triggering the short-circuit protection. It is
pin-compatible replacement for the HV9911.
a
EQUATION 3-2:
3.2
Linear Regulator
VINSTART = UVLOMAX + VDROP1
= 7V + 0.3V
= 7.3V
The HV9912 can be powered directly from its VIN pin
that withstands a voltage of up to 90V. When a voltage
is applied to the VIN pin, the HV9912 tries to maintain a
constant 7.75V (typical) at the VDD pin. The regulator
also has a built-in undervoltage lockout which shuts off
the IC if the voltage at the VDD pin falls below the UVLO
threshold.
EQUATION 3-3:
V
INSTOP= UVLOMAX – UVLO + VDROP
= 7V – 0.5V + 1.25V
= 7.75V
The VDD pin must be bypassed by a low-ESR capacitor
(≥0.1 µF) to provide a low-impedance path for the
high-frequency current of the output gate driver.
Minimum Voltage Drop vs. IIN
3
The input current drawn from the VIN pin is the sum of
the 1.5 mA current drawn by the internal circuit and the
current drawn by the gate driver, which in turn depends
on the switching frequency and the gate charge of the
external FET. See Equation 3-1.
2.5
2
TA = 85OC
1.5
1
TA = 25OC
EQUATION 3-1:
IIN = 1.5mA + QG fS
0.5
0
In the above equation, fS is the switching frequency,
and QG is the external FET’s gate charge, which can be
obtained from the data sheet of the FET.
0
2
4
8
10
IIN (mA) 6
FIGURE 3-1:
Headroom vs. Input Current.
In this case, the gate driver draws too much current and
VINSTART is less than VINSTOP. When this happens, the
IC will oscillate between ON and OFF if the input
DS20005583A-page 8
2016 Microchip Technology Inc.
HV9912
voltage is between the start and stop voltages.
Therefore, it is recommended that the input voltage be
3.7
Slope Compensation
For Continuous Conduction mode converters operating
in the Constant Frequency mode, slope compensation
becomes necessary to ensure stability of the Peak
Current mode controller if the operating duty cycle is
greater than 50%. Choosing a slope compensation
which is one half of the down slope of the inductor
current ensures that the converter will be stable for all
duty cycles.
kept higher than VINSTOP
.
3.4
Reference
HV9912 includes a 2% accurate 1.25V reference,
which can be used as the reference for the output
current as well as to set the switch current limit. The
reference is buffered so that it can deliver a maximum
of 500 µA external current to drive the external circuitry.
The reference should be bypassed with at least a 10 nF
low-ESR capacitor.
Slope compensation can be programmed by two
resistors RSLOPE and RSC. Assuming a down slope of
DS (A/µs) for the inductor current, the slope
compensation resistors can be computed as illustrated
in Equation 3-5.
Note:
To avoid abnormal Startup conditions, the
bypass capacitor at the REF pin should
not exceed 0.1 µF.
EQUATION 3-5:
3.5
Oscillator
RSLOPE DS 106 TS RCS
-------------------------------------------------------------------------
=
RSC
Connecting the resistor between RT and GND will
program the time period.
10
Where RCS is the current sense resistor which
senses the switching FET current
In both cases, resistor RT sets the current, which
charges an internal oscillator capacitor. The capacitor
voltage ramps up linearly. When the voltage increases
beyond the internal set voltage, a comparator triggers
the set input of the internal SR flip-flop. This starts the
next switching cycle. The time period of the oscillator
can be computed as shown in Equation 3-4.
Note:
The maximum current that can be sourced
out of the SC pin is 100 µA. This limits the
minimum value of the RSLOPE resistor to
25 kΩ. If the equation for slope
compensation produces a RSLOPE less
than this value, then RSC would have to be
reduced accordingly. It is recommended
that RSLOPE be chosen within the range of
25 kΩ to 50 kΩ.
EQUATION 3-4:
TS RT 18pF
3.6
Synchronization
The SYNC pin is an input/output (I/O) port to a
fault-tolerant peer-to-peer and/or master clock
synchronization circuit. For synchronization, the SYNC
pins of multiple HV9912-based converters can be
connected together and may also be connected to the
open drain output of a master clock. When connected
in this manner, the oscillators will lock to the device with
the highest operating frequency. When synchronizing
multiple ICs, it is recommended that the same timing
resistor (corresponding to the switching frequency) be
used in all the HV9912 circuits.
3.8
Current Sense
The current sense input of the HV9912 includes a
built-in 100 ns (minimum) blanking time to prevent
spurious turn-off due to the initial current spike when
the FET turns on.
The HV9912 includes two high-speed comparators—
one is used during normal operation and the other is
used to limit the maximum input current during Input
Undervoltage or Overload conditions.
On rare occasions, given the length of the connecting
lines for the SYNC pins, a resistor between SYNC and
GND may be required to damp any ringing due to
parasitic capacitances. It is recommended that the
resistor chosen be greater than 300 kΩ.
The IC includes an internal resistor divider network,
which steps down the voltage at the COMP pin by a
factor of 15. This stepped-down voltage is given to one
of the comparators as the current reference. The
reference to the other comparator, which acts to limit
the maximum inductor current, is given externally.
When synchronized in this manner, a permanent High
or Low condition on the SYNC pin will result in a loss of
synchronization, but the HV9912-based converters will
continue to operate at their individually set operating
frequencies. Since loss of synchronization will not
result in total system failure, the SYNC pin is
considered fault tolerant.
It is recommended that the sense resistor RCS be
chosen so as to provide about 250 mV current sense
signal.
2016 Microchip Technology Inc.
DS20005583A-page 9
HV9912
capacitor maintains the voltage across it. The GATE is
disabled, so the converter stops switching and the
FAULT pin goes low, turning off the disconnect switch.
3.9
Current Limit
Current limit has to be set by a resistor divider from the
1.25V reference available on the IC. Assuming a
maximum operating inductor current Ipk (including
ripple current), the maximum voltage at the CLIM pin
can be set as shown in Equation 3-6.
The output capacitor of the converter determines the
converter’s PWM dimming response because the
capacitor has to get charged and discharged whenever
the PWMD signal goes high or low. In the case of a
buck converter, since the inductor current is
continuous, a very small capacitor is used across the
LEDs. This minimizes the effect of the capacitor on the
converter’s PWM dimming response. However, in the
case of a boost converter, the output current is
discontinuous, and a very large output capacitor is
required to reduce the ripple in the LED current. Thus,
this capacitor will have a significant impact on the PWM
dimming response. By turning off the disconnect switch
when PWMD goes low, the output capacitor is
prevented from being discharged. This dramatically
improves the boost converter’s PWM dimming
response.
EQUATION 3-6:
VCLIM 1.2 IPK RCS + 5 RCS RSLOPE 0.9
Note that this equation assumes a current limit at 120%
of the maximum input current. Also, if VCLIM is greater
than 450 mV, the saturation of the internal opamp will
determine the limit on the input current rather than the
CLIM pin. In such a case, the sense resistor RCS should
be reduced until VCLIM reduces below 550 mV.
It is recommended that no capacitor be connected
between CLIM and GND.
Note:
In case of Continuous Conduction mode
boost converters, disconnecting the
capacitor might cause a sudden spike in
the capacitor voltage as the energy in the
inductor is dumped into the capacitor. This
increase in the capacitor voltage might
cause the OVP comparator to trip if the
OVP point is set too close to the maximum
operating voltage. Thus, either the capac-
itor has to be larger to absorb this energy
without increasing the capacitor voltage
significantly or the OVP set point has to be
increased.
3.10 Internal 1 MHz Transconductance
Amplifier
HV9912 includes a built-in 1 MHz transconductance
amplifier with tri-state output, which can be used to
close the feedback loop. The output current sense
signal is connected to the FDBK pin and the current
reference is connected to the IREF pin.
The output of the opamp is controlled by the signal
applied to the PWMD pin. When PWMD is high, the
output of the opamp is connected to the COMP pin.
When PWMD is low, the output is left open. This
enables the integrating capacitor to hold the charge
when the PWMD signal has turned off the gate drive.
When the IC is enabled, the voltage on the integrating
capacitor will force the converter into Steady state
almost instantaneously.
3.12 False Triggering of the
Short-Circuit Comparator During
PWM Dimming
The output of the opamp is buffered and connected to
the current sense comparator using a 15:1 divider. The
buffer helps to prevent the integrator capacitor from
discharging during the PWM Dimming state.
During PWM dimming, the parasitic capacitance of the
LED string causes a spike in the output current when
the disconnect FET is turned on. With the HV9911, this
parasitic spike in the output current makes the IC
falsely detect an Overcurrent condition and shut down.
To prevent this false shutdown, an R-C filter is used at
the FDBK pin to filter this spike.
3.11 PWM Dimming
PWM dimming can be achieved by driving the PWMD
pin with a TTL-compatible square wave source. The
PWM signal is connected internally to three different
nodes—the transconductance amplifier, the FAULT
output and the GATE output.
To prevent false triggering in the HV9912, there is a
built-in 500 ns blanking network for the short-circuit
comparator, which eliminates the need for the external
R-C low-pass filter. This blanking network is activated
when the PWMD input goes high. Thus, the
short-circuit comparator will not see the spike in the
LED current during the PWM Dimming turn-on
transition. Once the blanking timer is completed, the
short-circuit comparator will start monitoring the output
current. Thus, the total delay time for detecting a
short-circuit will depend on the condition of the PWMD
input.
When the PWMD signal is high, the GATE and FAULT
pins are enabled and the transconductance opamp’s
output is connected to the external compensation
network. Thus, the internal amplifier controls the output
current. When the PWMD signal goes low, the output of
the transconductance amplifier is disconnected from
the compensation network. Therefore the integrating
DS20005583A-page 10
2016 Microchip Technology Inc.
HV9912
If the output short-circuit exists before the PWMD
signal goes high, the total detection can be computed
as shown in Equation 3-7:
This equation assumes that the voltage drop across RZ
can be neglected compared to the voltage swing at the
COMP pin, which is true in most cases (RZ < 100 kꢀ).
The POR time (tPOR) for the HV9912 is 10 μs.
EQUATION 3-7:
VIN
tdetect = tblank SCmax + tdelaymax 900 + 250
1150nsmax
If the short-circuit occurs when the PWMD signal is
already high, the time to detect is determined through
Equation 3-8:
POR
EQUATION 3-8:
Pull-up
with 5.0µA
Pull-down
with 5.0µA
tdetect1 = tdelaymax 250nsmax
Gm control
COMP
5.0V
3.13 Hiccup Timer
HV9912 reuses the compensation network on the
COMP pin to create a timer which is activated upon
startup or when a detected Fault has been cleared.
When a Fault is detected (either open-circuit or
short-circuit) or upon startup, the COMP pin is
disconnected from the gM amplifier and the GATE and
FAULT pins are pulled low, disabling the LED driver.
When the Fault has cleared, a 5 µA current source is
activated which pulls the COMP network up to 5V.
Once the voltage at the COMP network reaches 5V, the
5 µA sourcing current is disconnected and a 5 µA
sinking current is activated which pulls the COMP pin
low. When the voltage at the COMP pin reaches 1V, the
sinking current is disconnected and the gM amplifier is
reconnected to the COMP pin. The FAULT pin goes
high and the GATE pin would be allowed to switch. The
closed-loop control then takes over the control of the
LED current.
1.0V
tPOR
FLT
tDELAY
FIGURE 3-2:
Waveforms during Startup.
3.15 Fault Condition
In the case of a Fault condition (either open-circuit or
short-circuit), the same sequence is repeated, and the
only difference is that the COMP pin voltage does not
start from zero but from its Steady-state condition.
3.16 Short-Circuit Protection
3.14 Startup Condition
When a Short-circuit condition is detected (output
current becomes higher than twice the Steady-state
current), the GATE and FAULT outputs are pulled low.
As soon as the disconnect FET is turned off, the output
current goes to zero and the Short-circuit condition
disappears. At this time, the hiccup timer is started.
(See Figure 3-3.) Once the timing is complete, the
converter attempts to restart. If the Fault condition still
persists, the converter shuts down and goes through
the cycle again. If the Fault condition is cleared due to
a momentary output short, the converter will start
regulating the output current normally. This allows the
LED driver to recover from accidental shorts without
having to reset the IC.
The startup waveforms are shown in Figure 3-2.
Assuming a pole-zero R-C network at the COMP pin
(series combination of RZ and CZ in parallel with CC),
the start-up delay time can be approximately computed
as shown in Equation 3-9.
EQUATION 3-9:
9V
5A
----------
tdelay tPOR + CC + CZ
The hiccup time will depend on the Steady-state
voltage of the COMP pin (VCOMP). This is typically in
the range of 3V–4V. The hiccup time can be
approximately computed with Equation 3-10.
2016 Microchip Technology Inc.
DS20005583A-page 11
HV9912
the LED string voltage, at which point no Fault will be
detected and the normal operation of the circuit will
commence. (See Figure 3-4.)
EQUATION 3-10:
9V – VCOMP
------------------------------
5A
tHICCUP CC + CZ
The various delay times can be determined as shown
in Equation 3-11, Equation 3-12 and Equation 3-13:
EQUATION 3-11:
Output Current
Short Circuit
Occurs
tRC 0.1 ROVP1 + ROVP2 CO
Normal Operation
Resumes
EQUATION 3-12:
9V – VCOMP
FLT
------------------------------
tHICCUP1 CC + CZ
Hiccup Time
5A
EQUATION 3-13:
tHICCUP2 – n CC + CZ
9V
5A
COMP
----------
5.0V
1.0V
Note:
The number of hiccup cycles might be
more than two.
tHICCUP
3.18 Linear Dimming
FIGURE 3-3:
Short-circuit Protection.
Linear dimming can be achieved by varying the voltage
at the IREF pin because the output current is
proportional to the voltage at the pin. This can be done
either by using a potentiometer from the IREF pin or
applying an external voltage source to the pin.
3.17 Overvoltage Protection
The HV9912 provides hysteretic overvoltage
protection, allowing the IC to recover in case the LED
load is disconnected momentarily.
In the HV9911, due to the offset voltage of the
short-circuit comparator as well as the non-linearity of
the X2 gain stage, pulling the IREF pin very close to
GND will cause the internal short-circuit comparator to
trigger and shut down the IC.
When the load is disconnected in a boost converter, the
output voltage rises as the output capacitor starts
charging. When the output voltage reaches the OVP
rising threshold, the HV9912 detects an Overvoltage
condition and turns off the converter. The converter is
turned back on only when the output voltage falls below
the falling OVP threshold, which is 10% lower than the
rising threshold. This time is mostly dictated by the R-C
time constant of the output capacitor CO and the
To overcome this in the HV9912, the minimum output
of the gain stage is limited to 125 ~ 250mV, allowing the
IREF pin to be pulled all the way to 0V without triggering
the short-circuit comparator.
Note:
Since this control IC is a Peak Current
mode controller, pulling the IREF pin to
zero will not cause the LED current to
become zero. The converter will still be
operating at its minimum on time, causing
a very small current to flow through the
LEDs. To get zero LED current, the
PWMD input has to be pulled to GND.
resistor network used to sense overvoltage (ROVP1
+
ROVP2). In case of a persistent Open-circuit condition,
this cycle keeps repeating, maintaining the output
voltage within a 10% band.
In most designs, the lower threshold voltage of the
overvoltage protection is more than the LED string
voltage when the converter is turned on. Thus, when
the LED load is reconnected to the output of the
converter, the voltage differential between the actual
output voltage and the LED string voltage will cause a
spike in the output current when the FAULT signal goes
high. This causes a short-circuit to be detected and the
HV9912 will go into short-circuit protection. This
continues until the output voltage becomes lower than
DS20005583A-page 12
2016 Microchip Technology Inc.
HV9912
OVP ON
LED string reconnects
OVP OFF
Output Cap
Voltage
100V
90V
LED string voltage
80V
LED string disconnects
FLT
tRC
tHICCUP1
tHICCUP2
Output Current
COMP
5V
1V
FIGURE 3-4:
Open-circuit Protection.
2016 Microchip Technology Inc.
DS20005583A-page 13
HV9912
4.0
4.1
PACKAGING INFORMATION
Package Marking Information
16-lead SOIC
Example
e3
e3
HV9912NG
1612389
XXXXXXXXX
YYWWNNN
Legend: XX...X Product Code or Customer-specific information
Y
YY
WW
NNN
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
e
3
*
This package is Pb-free. The Pb-free JEDEC designator ( )
e
3
can be found on the outer packaging for this package.
Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for product code or customer-specific information. Package may or
not include the corporate logo.
DS20005583A-page 14
2016 Microchip Technology Inc.
HV9912
16-Lead SOIC (Narrow Body) Package Outline (NG)
9.90x3.90mm body, 1.75mm height (max), 1.27mm pitch
θ1
D
16
E1 E
Note 1
(Index Area
D/2 x E1/2)
Gauge
Plane
L2
1
L
Seating
Plane
θ
L1
Top View
View B
View
B
A
h
Note 1
A A2
h
Seating
Plane
e
b
A1
Side View
A
View A-A
Note: For the most current package drawings, see the Microchip Packaging Specification at www.microchip.com/packaging.
Note:
1. 7KLVꢁFKDPIHUꢁIHDWXUHꢁLVꢁRSWLRQDOꢂꢁ,IꢁLWꢁLVꢁQRWꢁSUHVHQWꢃꢁWKHQꢁDꢁ3LQꢁꢄꢁLGHQWL¿HUꢁPXVWꢁEHꢁORFDWHGꢁLQꢁWKHꢁLQGH[ꢁDUHDꢁLQGLFDWHGꢂꢁ7KHꢁ3LQꢁꢄꢁLGHQWL¿HUꢁFDQꢁEHꢅꢁ
DꢁPROGHGꢁPDUNꢆLGHQWL¿HUꢇꢁDQꢁHPEHGGHGꢁPHWDOꢁPDUNHUꢇꢁRUꢁDꢁSULQWHGꢁLQGLFDWRUꢂ
Symbol
A
A1
MIN 1.35* 0.10 1.25 0.31 9.80* 5.80* 3.80*
NOM 9.90 6.00 3.90
MAX 1.75 0.25 1.65* 0.51 10.00* 6.20* 4.00*
A2
b
D
E
E1
e
h
L
L1
L2
ș
0O
-
șꢀ
5O
-
0.25 0.40
Dimension
(mm)
1.27
BSC
1.04 0.25
REF BSC
-
-
-
-
-
-
0.50 1.27
8O 15O
JEDEC Registration MS-012, Variation AC, Issue E, Sept. 2005.
ꢀꢁ7KLVꢁGLPHQVLRQꢁLVꢁQRWꢁVSHFL¿HGꢁLQꢁWKHꢁ-('(&ꢁGUDZLQJꢂ
Drawings are not to scale.
2016 Microchip Technology Inc.
DS20005583A-page 15
HV9912
NOTES:
DS20005583A-page 16
2016 Microchip Technology Inc.
HV9912
APPENDIX A: REVISION HISTORY
Revision A (July 2016)
• Converted Supertex Doc# DSFP-HV9912 to
Microchip DS20005583A.
• Made minor text changes throughout the docu-
ment.
DS20005583A-page 17
2016 Microchip Technology Inc.
HV9912
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, contact your local Microchip representative or sales office.
Examples:
XX
PART NO.
Device
-
X
-
X
a) HV9912NG-G:
Switch-Mode LED Driver IC with
High Current Accuracy and Hic-
cup Mode Protection, 16-lead
SOIC Package, 45/Tube
Package
Options
Environmental
Media Type
b) HV9912NG-G-M901: Switch-Mode LED Driver IC with
High Current Accuracy and Hic-
cup Mode Protection, 16-lead
SOIC Package, 2600/Reel
c) HV9912NG-G-M934: Switch-Mode LED Driver IC with
High Current Accuracy and Hic-
Device:
HV9912
=
Switch-Mode LED Driver IC with High
Current Accuracy and Hiccup Mode
Protection
cup Mode Protection, 16-lead
SOIC Package, 2600/Reel
Package:
NG
G
=
=
16-lead SOIC
Environmental:
Media Types:
Lead (Pb)-free/RoHS-compliant Package
(blank)
M901
M934
=
=
=
45/Tube for an NG Package
2600/Reel for an NG Package
2600/Reel for an NG Package
Note: For media types M901 and M934, the base quantity for tape and reel
was standardized to 2600/reel. Both options will result in delivery of the
same number of parts/reel.
2016 Microchip Technology Inc.
DS20005583A-page 18
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights unless otherwise stated.
Trademarks
The Microchip name and logo, the Microchip logo, AnyRate,
dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KeeLoq,
KeeLoq logo, Kleer, LANCheck, LINK MD, MediaLB, MOST,
MOST logo, MPLAB, OptoLyzer, PIC, PICSTART, PIC32 logo,
RightTouch, SpyNIC, SST, SST Logo, SuperFlash and UNI/O
are registered trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
ClockWorks, The Embedded Control Solutions Company,
ETHERSYNCH, Hyper Speed Control, HyperLight Load,
IntelliMOS, mTouch, Precision Edge, and QUIET-WIRE are
registered trademarks of Microchip Technology Incorporated
in the U.S.A.
Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut,
BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM,
dsPICDEM.net, Dynamic Average Matching, DAM, ECAN,
EtherGREEN, In-Circuit Serial Programming, ICSP, Inter-Chip
Connectivity, JitterBlocker, KleerNet, KleerNet logo, MiWi,
motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB,
MPLINK, MultiTRAK, NetDetach, Omniscient Code
Generation, PICDEM, PICDEM.net, PICkit, PICtail,
PureSilicon, RightTouch logo, REAL ICE, Ripple Blocker,
Serial Quad I/O, SQI, SuperSwitcher, SuperSwitcher II, Total
Endurance, TSHARC, USBCheck, VariSense, ViewSpan,
WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
GestIC is a registered trademarks of Microchip Technology
Germany II GmbH & Co. KG, a subsidiary of Microchip
Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
QUALITYꢀMANAGEMENTꢀꢀSYSTEMꢀ
CERTIFIEDꢀBYꢀDNVꢀ
© 2016, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
ISBN: 978-1-5224-0798-0
== ISO/TSꢀ16949ꢀ==ꢀ
2016 Microchip Technology Inc.
DS20005583A-page 19
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Asia Pacific Office
China - Xiamen
Tel: 86-592-2388138
Fax: 86-592-2388130
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
China - Zhuhai
Tel: 86-756-3210040
Fax: 86-756-3210049
Denmark - Copenhagen
Tel: 45-4450-2828
Fax: 45-4485-2829
Hong Kong
Tel: 852-2943-5100
Fax: 852-2401-3431
India - Bangalore
Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
France - Paris
Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
Web Address:
www.microchip.com
India - New Delhi
Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
Germany - Dusseldorf
Tel: 49-2129-3766400
Atlanta
Duluth, GA
Tel: 678-957-9614
Fax: 678-957-1455
China - Beijing
Tel: 86-10-8569-7000
Fax: 86-10-8528-2104
Germany - Karlsruhe
Tel: 49-721-625370
India - Pune
Tel: 91-20-3019-1500
China - Chengdu
Tel: 86-28-8665-5511
Fax: 86-28-8665-7889
Germany - Munich
Tel: 49-89-627-144-0
Fax: 49-89-627-144-44
Austin, TX
Tel: 512-257-3370
Japan - Osaka
Tel: 81-6-6152-7160
Fax: 81-6-6152-9310
Boston
China - Chongqing
Tel: 86-23-8980-9588
Fax: 86-23-8980-9500
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
Westborough, MA
Tel: 774-760-0087
Fax: 774-760-0088
Japan - Tokyo
Tel: 81-3-6880- 3770
Fax: 81-3-6880-3771
China - Dongguan
Tel: 86-769-8702-9880
Italy - Venice
Tel: 39-049-7625286
Chicago
Itasca, IL
Tel: 630-285-0071
Fax: 630-285-0075
Korea - Daegu
Tel: 82-53-744-4301
Fax: 82-53-744-4302
China - Guangzhou
Tel: 86-20-8755-8029
Netherlands - Drunen
Tel: 31-416-690399
Fax: 31-416-690340
China - Hangzhou
Tel: 86-571-8792-8115
Fax: 86-571-8792-8116
Korea - Seoul
Cleveland
Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
Poland - Warsaw
Tel: 48-22-3325737
Independence, OH
Tel: 216-447-0464
Fax: 216-447-0643
China - Hong Kong SAR
Tel: 852-2943-5100
Fax: 852-2401-3431
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
Malaysia - Kuala Lumpur
Tel: 60-3-6201-9857
Fax: 60-3-6201-9859
Dallas
Addison, TX
Tel: 972-818-7423
Fax: 972-818-2924
China - Nanjing
Tel: 86-25-8473-2460
Fax: 86-25-8473-2470
Sweden - Stockholm
Tel: 46-8-5090-4654
Malaysia - Penang
Tel: 60-4-227-8870
Fax: 60-4-227-4068
Detroit
Novi, MI
Tel: 248-848-4000
UK - Wokingham
Tel: 44-118-921-5800
Fax: 44-118-921-5820
China - Qingdao
Tel: 86-532-8502-7355
Fax: 86-532-8502-7205
Philippines - Manila
Tel: 63-2-634-9065
Fax: 63-2-634-9069
Houston, TX
Tel: 281-894-5983
China - Shanghai
Tel: 86-21-5407-5533
Fax: 86-21-5407-5066
Singapore
Tel: 65-6334-8870
Fax: 65-6334-8850
Indianapolis
Noblesville, IN
Tel: 317-773-8323
Fax: 317-773-5453
China - Shenyang
Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
Taiwan - Hsin Chu
Tel: 886-3-5778-366
Fax: 886-3-5770-955
Los Angeles
China - Shenzhen
Tel: 86-755-8864-2200
Fax: 86-755-8203-1760
Mission Viejo, CA
Tel: 949-462-9523
Fax: 949-462-9608
Taiwan - Kaohsiung
Tel: 886-7-213-7828
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
Taiwan - Taipei
Tel: 886-2-2508-8600
Fax: 886-2-2508-0102
New York, NY
Tel: 631-435-6000
San Jose, CA
Tel: 408-735-9110
China - Xian
Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
Canada - Toronto
Tel: 905-695-1980
Fax: 905-695-2078
06/23/16
DS20005583A-page 20
2016 Microchip Technology Inc.
相关型号：
HV9918K7-G
LED Driver, 1-Segment, 3 X 3 MM, 0.80 MM HEIGHT, 0.65 MM PITCH, GREEN, MO-229WEEC-2, DFN-8
SUPERTEX
HV9919K7-G
LED Driver, 1-Segment, PDSO8, 3 X 3 MM, 0.80 MM HEIGHT, 0.65 MM PITCH, GREEN, MO-229WEEC-2, DFN-8
SUPERTEX
©2020 ICPDF网 联系我们和版权申明