HV9967B [SUPERTEX]

Integrated LED Driver with Average-Mode Current Control;


型号：	HV9967B
厂家：	Supertex, Inc
描述：	Integrated LED Driver with Average-Mode Current Control
文件：	总7页 (文件大小：862K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

Supertex inc.

HV9967B

Integrated LED Driver

with Average-Mode Current Control

Features

► 3% accurate LED current

General Description

The HV9967B is an average-mode current control LED driver IC

operating in a constant off-time mode.

► Integrated 60V, 0.8Ω MOSFET

► Low sensitivity to external component variation

► Single resistor LED current setting

► Fixed off-time control

The IC features an integrated 60V, 0.8Ω MOSFET that can be

used as a stand-alone buck converter switch, or connected as a

source driver for driving an external high-voltage depletion-mode

MOSFET. The HV9967B is powered through its switching output

when the integrated switch is off. Hence, the same external

MOSFET can be used as a high-voltage linear regulator for

powering the IC.

► PWM dimming input

► Output short circuit protection with skip mode

► Over-temperature protection

► Available in compact 8-Lead MSOP and 8-Lead

DFN packages

The LED current is programmed with one external resistor. The

average-mode current control method does not produce a peak-

to-average error, and therefore greatly improves current accuracy

and line and load regulation of the LED current without any need

for loop compensation or direct sensing of the LED current at a

high-voltage potential. The auto-zero circuit cancels the effects of

the input offset voltage and of the propagation delay of the current

sense comparator.

Applications

► DC/DC or AC/DC LED drivers

► RGB backlighting drivers for ﬂat panel displays

► General purpose constant current source

► Signage and decorative LED lighting

► Chargers

Typical Application Circuit

8.0 - 60VDC

C_O

C_IN

LED

String

PWMD

HV9967B

RSENSE

VDD

PGND AGND

R_SENSE

C_DD

R_T

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

Pin Conﬁgurations

Ordering Information

Part Number

HV9967BK7-G

HV9967BMG-G

Package Options

Packing

RSENSE

PGND

VDD

8-Lead DFN (3x3mm)

8-Lead MSOP

3000/Reel

2500/Reel

AGND

GND

-G indicates package is RoHS compliant (‘Green’)

PWMD

8-Lead DFN (K7)

(top view)

VDD

AGND

RSENSE

Absolute Maximum Ratings*

PGND

PWMD

Parameter

SW to GND

VDD to GND

Other I/O to GND

R_T, I_SET

Value

-0.5V to +65V

-0.3V to 6.0V

8-Lead MSOP (MG)

(top view)

-0.3V to (V_DD+ 0.3V)

2.0mA

Product Marking

Continuous power dissipation (T_A= +25°C)

8-Lead DFN (K7)

Y = Last Digit of Year Sealed

W = Code for Week Sealed

L = Lot Number

H67B

1.6W

350mW

YW LL

8-Lead MSOP (MG)

= “Green” Packaging

Junction temperature

-40°C to +150°C

-65°C to +150°C

Package may or may not include the following marks: Si or

Storage temperature range

8-Lead DFN (K7)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause

permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in

the operational sections of the speciﬁcations is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect device reliability.

Top Marking

967B

LLLL

L = Lot Number

YY = Year Sealed

WW = Week Sealed

Typical Thermal Resistance

Bottom Marking

Package

θ_ja

= “Green” Packaging

8-Lead DFN

8-Lead MSOP

37^OC/W

216^OC/W

YYWW

Package may or may not include the following marks: Si or

8-Lead MSOP (MG)

Electrical Characteristics

(The * denotes speciﬁcations which apply over the full operating ambient temperature range of -40°C < T_A< 125°C. Otherwise speciﬁcations are at T_A=

25°C. V_SW= 10V/10mA, V_DD= 5.0V unless otherwise noted)

Sym

Description

Min

Typ

Max Units Conditions

Input

V_SWDC

Input DC supply voltage range

8.0

DC input voltage

I_INSD

Shut-down mode supply current

0.5

1.0

Pin PWMD to GND

Notes:

Not production tested; guaranteed by design or characterization.

Speciﬁcations apply over the full operating ambient temperature range of -40°C < T_A< +125°C.

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

Electrical Characteristics (cont.)

(The * denotes speciﬁcations which apply over the full operating ambient temperature range of -40°C < T_A< 125°C. Otherwise speciﬁcations are at T_A=

25°C. V_SW= 10V/10mA, V_DD= 5.0V unless otherwise noted)

Sym

Description

Min

Typ

Max Units Conditions

Internal Regulator

VDD

UVLO

ΔUVLO

Internally regulated voltage

4.70 5.00 5.20

PWMD = V_DD; R_T= 100kΩ

V_DDrising, as needed to

ensure I_C(MIN)

V_DDundervoltage lockout threshold

4.10

4.70

V_DDundervoltage lockout hysteresis

150

V_DDfalling

PWM Dimming

V_EN(LO)

V_EN(HI)

R_EN

PWMD input low voltage

0.8

---

PWMD input high voltage

2.0

---

Internal pull down resistance at PWMD

100

150

kΩ

V_PWMD= 5.0V

Current Control

V_CS(TH)

R_SENSEcurrent threshold

243

0.1

257

mV/^OC

---

dV_CS/dt^OTemperature regulation

140

T_BLANK

Current sense blanking interval

290

950

---

T_ON(MIN)

Minimum ON-time

V_RSENSE= V_CS(TH)+ 50mV

Reduction in output LED

current occurs beyond this

duty cycle due to saturation

of T2 timers.

D_MAX

Maximum steady-state duty cycle

Short Circuit Protection

V_CS(SHORT)Hiccup threshold voltage at R_SENSE

355

440

150

---

T_DELAY

T_HICCUP

T_ON(MIN)

Current limit delay R_SENSEto SW-OFF

Hiccup time

800

V_RSENSE= V_CS(SHORT)+ 50mV

---

μs

Minimum ON-time (short circuit)

400

V_RSENSE= V_CS(SHORT)+ 50mV

T_OFFTimer

7.0

0.7

R_T= 400kΩ

R_T= 100kΩ

R_T= 10kΩ

T_OFF

OFF time

μs

1.0

1.2

SW Output

R_ON

ON resistance

0.8

V_DD= 5.0V

V_DD= 4.75V,

I_C

Continuous current

0.75

V_RSENSE= 370mV, V_SW=10V

Over-temperature Protection

T_SD

Shut-down temperature

125

^OC

---

ΔT_SD

Hysteresis

Notes:

Not production tested; guaranteed by design or characterization.

Speciﬁcations apply over the full operating ambient temperature range of -40°C < T_A< +125°C.

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

Functional Block Diagram

VDD

4.35V

HV9967B

UVLO

V_CS

REG

POR

L/E

Blanking

OTP

Average

Current

RSENSE

PWMD

PGND

Control Logic

V_CS

OUT

100kΩ

R Q

0.4V

S Q

PGND

SET

AGND

T_OFF

Timer

0.8ms

Application Information

Average Current Control Feedback and Output

Short Circuit Protection

General description

TheHV9967BemploysSupertex’proprietarycontrolscheme,

achieving fast and very accurate control of average current

in the buck inductor through sensing the switch current only.

No compensation of the current control loop is required. The

LED current response to PWMD input is similar to that of the

peak-current control ICs, such as HV9910B. The inductor

current ripple amplitude does not affect this control scheme

signiﬁcantly, and therefore, the LED current is independent

of the variation in inductance, switching frequency or output

voltage. Constant off-time control of the buck converter is

used for stability and to reduce input voltage regulation of

the LED current.

The constant-current control feedback derives the aver-

age current signal from the source current of the switching

MOSFET. This current is detected using a sense resistor at

the RSENSE pin. The feedback operates in a fast open-loop

mode. No compensation is required. Output current is pro-

grammed simply as:

0.25V

I_LED

(2)

R_CS

The above equation is only valid for continuous conduction

of the output inductor. It is a good practice to design the in-

ductor such that the switching ripple current in it is 30~40%

of its average full load DC current peak-to-peak. Hence, the

recommended inductance can be calculated as:

OFF Timer

The timing resistor connected to RT determines the off-time

of the gate driver, and it must be wired to VDD. The equation

governing the off-time of the GATE output is given by:

V_O(MAX)• T_OFF

L_O=

(3)

0.4 • I_O

_OFF= R_T• 100pF

(1)

The duty-cycle range of the current control feedback is lim-

ited to D ≤ 0.8. A reduction in the LED current may occur

when the LED string voltage V_Ois greater than 80% of the

input voltage V_INof the HV9967B LED driver.

within the range of 10kΩ ≤ R_T≤ 400kΩ.

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

Reducing the output LED voltage V_Obelow V_O(MIN)=V_IN• D_MIN

SW Input and Linear Regulator

where D_MIN= 0.8µs/(T_OFF+ 0.8µs), may also result in the loss

of regulation of the LED current. This condition, however,

causes increase in the LED current and can potentially trip

the short-circuit protection comparator threshold.

HV9967B includes an integrated 60V, 0.8Ω switching

MOSFET at the SW input. The power for the IC is supplied

from a linear 5.0V regulator that is also derived from the SW

input.

The short circuit protection comparator trips when the volt-

age at RSENSE exceeds 0.4V. When this occurs, the SW

off-time T_HICCUP= 800µs is generated to prevent stair-casing

of the inductor current and potentially its saturation due to

insufﬁcient output voltage. The typical short-circuit current is

shown in the waveform of Fig. 1.

PWM Dimming

The HV9967B features a TTL compatible dimming input

PWMD. Applying a square-wave voltage to PWMD will mod-

ulate the duty ratio of the LED current accordingly. The rising

and falling edges are limited by the current slew rate in the

inductor. The ﬁrst switching cycle is terminated upon reach-

ing the 250mV level at RSENSE. The circuit will reach the

steady state within 3~4 switching cycles regardless of the

switching frequency.

0.44V/R_SENSE

800µs

Over-Temperature Protection

The HV9967B includes over-temperature protection. Typi-

cally, when the junction temperature exceeds 145^OC, switch-

ing of the SW input is disabled. The switching resumes when

the temperature falls by approximately 20^OC from the trip

point.

Fig.1. Short-circuit inductor current.

A leading-edge blanking delay is provided at RSENSE to

prevent false triggering of the current feedback and the short

circuit protection.

Pin Description

Pin #

Function Description

Drain of 60V 0.8Ω NDMOS switch and input of H/V regulator.

Source of NDMOS switch and current sense input.

RSENSE

Connect a resistor to GND to program the output current and short circuit thresholds.

Power ground. Must be wired to AGND on PCB.

PGND

PWMD

PWM dimming input. This TTL input enables switching of SW when in high state.

No connection.

Resistor connected between RT and VDD programs the off-time of SW.

Analog ground (0V).

AGND

Power supply for all internal circuits. Bypass with a low ESR capacitor to PGND (>0.5μF).

Connect GATE of external depletion-mode NFET for high-voltage operation.

VDD

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

8-Lead DFN Package Outline (K7)

3.00x3.00mm body, 0.80mm height (max), 0.65mm pitch

Note 1

(Index Area

D/2 x E/2)

Note 1

(Index Area

D/2 x E/2)

View B

Top View

Bottom View

Note 3

Seating

Plane

Note 2

Notes:

1. A Pin 1 identiﬁer must be located in the index area indicated. The Pin 1 identiﬁer can be: a molded mark/identiﬁer; an embedded metal marker; or

a printed indicator.

2. Depending on the method of manufacturing, a maximum of 0.15mm pullback (L1) may be present.

3. The inner tip of the lead may be either rounded or square.

Symbol

1.60

1.35

0.00*

0^O

MIN

0.70

0.00

0.02

0.05

0.25

0.30

0.35

2.85*

3.00

3.15*

2.85*

3.00

3.15*

0.30

0.40

0.50

Dimension

(mm)

0.20

REF

0.65

BSC

NOM 0.75

MAX 0.80

2.50

1.75

0.15

14^O

JEDEC Registration MO-229, Variation WEEC-2, Issue C, Aug. 2003.

* This dimension is not speciﬁed in the JEDEC drawing.

Drawings not to scale.

Supertex Doc. #: DSPD-8DFNK73X3P065, Version C081109.

Doc.# DSFP-HV9967B

B060712

Supertex inc.

www.supertex.com

HV9967B

8-Lead MSOP Package Outline (MG)

3.00x3.00mm body, 1.10mm height (max), 0.65mm pitch

θ1 (x4)

Gauge

Plane

Note 1

(Index Area

D/2 x E1/2)

Seating

Plane

Top View

View B

Seating

Plane

View A-A

Side View

Note:

1. A Pin 1 identiﬁer must be located in the index area indicated. The Pin 1 identiﬁer can be: a molded mark/identiﬁer; an embedded metal marker; or

a printed indicator.

Symbol

0.22 2.80* 4.65* 2.80*

3.00 4.90 3.00

0.38 3.20* 5.15* 3.20*

0^O

θ1

5^O

MIN 0.75* 0.00

0.75

0.85

0.95

0.40

0.60

0.80

Dimension

(mm)

0.65

BSC

0.95

REF BSC

0.25

NOM

MAX 1.10

0.15

8^O

15^O

JEDEC Registration MO-187, Variation AA, Issue E, Dec. 2004.

* This dimension is not speciﬁed in the JEDEC drawing.

Drawings are not to scale.

Supertex Doc. #: DSPD-8MSOPMG, Version H041309.

(The package drawing(s) in this data sheet may not reﬂect the most current speciﬁcations. For the latest package outline

information go to http://www.supertex.com/packaging.html.)

Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives

an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability

to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and

specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com)

Supertex inc.

1235 Bordeaux Drive, Sunnyvale, CA 94089

Tel: 408-222-8888

www.supertex.com

Doc.# DSFP-HV9967B

B060712

HV9967B [SUPERTEX]

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