MAX16962SATEA/V+ [MAXIM]
Switching Regulator, 5.2A, BICMOS, 4 X 4 MM, ROHS COMPLIANT, TQFN-16;
| 型号： | MAX16962SATEA/V+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switching Regulator, 5.2A, BICMOS, 4 X 4 MM, ROHS COMPLIANT, TQFN-16 信息通信管理 开关 |
| 文件： | 总13页 (文件大小：552K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
General Description
Benefits and Features
The MAX16962 is a high-efficiency, synchronous step-
down converter that operates with a 2.7V to 5.5V input
voltage range and provides a 0.8V to 3.6V output voltage
range. The wide input/output voltage range and the abil-
ity to provide up to 4A to load current make this device
ideal for on-board point-of-load and post-regulation
applications. The MAX16962 achieves -3.7%/+2.6% out-
put error over load, line, and temperature ranges.
S Small External Components
2.2MHz Operating Frequency
S Ideal for Point-of-Load Applications
4A Maximum Load Current
Adjustable Output Voltage: 0.8V to 3.6V
2.7V to 5.5V Operating Supply Voltage
S High Efficiency at Light Load
26µA Skip Mode Quiescent Current
The MAX16962 features a 2.2MHz fixed-frequency PWM
mode for better noise immunity and load transient
response, and a pulse frequency modulation mode
(SKIP) for increased efficiency during light-load opera-
tion. The 2.2MHz frequency operation allows for the use
of all-ceramic capacitors and minimizes external compo-
nents. The optional spread-spectrum frequency modula-
tion minimizes radiated electromagnetic emissions.
S Minimizes Electromagnetic Interference
Programmable SYNC I/O Pin
Operates Above AM-Radio Band
Available Spread Spectrum
S Low Power Mode Saves Energy
1µA Shutdown Current
Open-Drain Power-Good Output
Integrated low R
heavy loads and make the layout a much simpler task
with respect to discrete solutions.
switches improve efficiency at
DSON
S Limits Inrush Current During Startup
Soft-Start
S Overtemperature and Short-Circuit Protections
The MAX16962 is offered with factory-preset output
voltages or with an adjustable output voltage. (See the
Selector Guide for options). Factory preset output volt-
age versions allow customers to achieve -3.7%/+2.6%
output voltage accuracy without using external resistors,
while the adjustable output voltage version provides the
flexibility to set the output voltage to any desired value
between 0.8V to 3.6V using an external resistive divider.
S 4mm x 4mm, 16-Pin Thin QFN and 16-Pin TSSOP
Packages
S -40°C to 125°C Operating Temperature Range
Applications
Automotive Infotainment
Point-of-Load Applications
Industrial/Military
Additional features include 8ms soft-start, 16ms power-
good output delay, overcurrent, and overtemperature
protections.
The MAX16962 is available in thermally enhanced
Typical Application Circuit
16-pin TSSOP-EP and 4mm
x
4mm, 16-pin
TQFN-EP packages, and is specified for operation over
the -40NC to +125NC automotive temperature range.
V
PV1
PV1
PV2
EN
OUTS
0.47µH
4.7µF
V
LX1
LX2
OUT1
Ordering Information appears at end of data sheet.
47µF
PGND1
PGND2
V
OUT1
V
PV
10Ω
1µF
MAX16962
PV
20kΩ
GND
PG
EP
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-6213; Rev 3; 7/15
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
ABSOLUTE MAXIMUM RATINGS
PV, PV1, PV2 to GND..............................................-0.3V to +6V
EN, PG to GND .......................................................-0.3V to +6V
PGND1 and PGND2 to GND ..............................-0.3V to +0.3V
LX1, LX2 Continuous RMS Current
(LX1 connected in Parallel with LX2)...................................4A
LX Current (LX1 connected in Parallel with LX2).....Q6A (Note 5)
Continuous Power Dissipation (T = +70NC)
A
TQFN (derate 25mW/NC above +70NC)................... 2000mW*
TSSOP (derate 26.1mW/NC above +70NC)........... 2088.8mW*
Operating Temperature Range........................ -40NC to +125NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
All Other Pins Voltages to GND .. (V + 0.3V) to (V
- 0.3V)
PV
GND
Output Short-Circuit Duration....................................Continuous
*As per JEDEC51 Standard (multilayer board).
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TQFN
TSSOP
Junction-to-Ambient Thermal Resistance (B ) ..........40NC/W
Junction-to-Ambient Thermal Resistance (B )....38.3NC/W
JA
JA
Junction-to-Case Thermal Resistance (B ).................6NC/W
Junction-to-Case Thermal Resistance (B )..............3NC/W
JC
JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V = V
= V
= 5V, V = 5V, T = T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)
PV
PV1
PV2 EN A J A
PARAMETER
SYMBOL
VPV
CONDITIONS
Normal operation
MIN
2.7
12
TYP
MAX
5.5
45
UNITS
V
Supply Voltage Range
Supply Current
IPV
No load, VPWM = 0V
VEN = 0V, TA = +25°C
26
1
FA
Shutdown Supply Current
ISHDN
5
FA
Undervoltage Lockout Threshold
Low
VUVLO_L
VUVLO_H
2.37
V
Undervoltage Lockout Threshold
High
2.6
V
V
Undervoltage Lockout Hysteresis
0.07
SYNCHRONOUS STEP-DOWN DC-DC CONVERTER
FB Regulation Voltage
VOUTS
800
0
mV
%
ILOAD = 4A
ILOAD = 0A
-3.7
-1.9
+2.6
+2.6
Feedback Set-Point Accuracy
VOUTS
VPV1 = 5V, ILX_ = 0.4A,
LX1 in parallel with LX2
pMOS On-Resistance
nMOS On-Resistance
RDSON_P
RDSON_N
34
25
55
45
mI
mI
VPV1 = 5V, ILX_ = 0.8A,
LX1 in parallel with LX2
Maxim Integrated
2
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(V = V
= V
= 5V, V = 5V, T = T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)
PV
PV1
PV2 EN A J A
Maximum pMOS Current-Limit
Threshold
ILIMP1
LX1 and LX2 shorted together
5.2
6.8
8.5
A
PARAMETER
SYMBOL
CONDITIONS
(VOUT + 0.5V P VPV1 P 5.5V) (Note 3)
Fixed output voltage variants
Adjustable output version
MIN
4.4
1
TYP
MAX
UNITS
Maximum Output Current
IOUT
A
2
5
OUTS Bias Current
IB_OUTS
ILX_LEAK
FA
FA
-1
+1
VPV_ = 5V, LX_ = PGND_ or PV_,
TA = +25°C
LX_ Leakage Current
-1
+1
Minimum On-Time
tON_MIN
RLX
60
24
ns
I
LX Discharge Resistance
Maximum Short-Circuit Current
OSCILLATOR
VEN = 0V, through the OUTS pin
15
55
10.4
A
Oscillator Frequency
fSW
Df/f
Internally generated
2.0
1.7
2.2
+6
2.4
2.4
MHz
%
Spread Spectrum
Spread-spectrum enabled
50% duty cycle (Note 4)
SYNC Input Frequency Range
THERMAL OVERLOAD
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
POWER-GOOD OUTPUT (PG)
PG Overvoltage Threshold
PG Undervoltage Threshold
PG Timeout Period
fSYNC
MHz
+165
15
°C
°C
PGOVTH
PGUVTH
Percentage of nominal output
Percentage of nominal output
106
90
110
92
114
94
%
%
16
ms
Undervoltage/Overvoltage
Propagation Delay
28
Fs
FA
V
Output High Leakage Current
TA = +25°C
0.2
0.4
0.4
ISINK = 3mA
PG Output Low Voltage
VPV = 1.2V, ISINK = 100FA
ENABLE INPUTS (EN)
Input Voltage High
Input Voltage Low
Input Hysteresis
VINH
VINL
Input rising
Input falling
2.4
V
V
0.5
0.85
1.0
V
Input Current
VEN = high
VEN = low
0.1
50
2
FA
kI
Pulldown Resistor
100
200
DIGITAL INPUTS (PWM, SYNC AS INPUT)
Input Voltage High
Input Voltage Low
VINH
VINL
1.8
V
V
0.4
Maxim Integrated
3
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(V = V
= V
= 5V, V = 5V, T = T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C.) (Note 2)
PV
PV1
PV2 EN A J A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
50
MAX
200
0.4
UNITS
mV
Input Voltage Hysteresis
Pulldown Resistor
50
100
kI
DIGITAL OUTPUT (SYNC AS OUTPUT)
Output Voltage Low
Output Voltage High
VOL
VOH
ISINK = 3mA
VPV = 5V, ISOURCE = 3mA
V
V
4.2
Note 2: All limits are 100% production tested at +25°C. Limits over temperature are guaranteed by design.
Note 3: Calculated value based on an assumed inductor current ripple of 30%.
Note 4: For SYNC frequency outside (1.7, 2.4) MHz, contact factory.
Note 5: LX_ has internal clamp diodes to PGND_ and IN_. Applications that forward bias these diodes should take care not to
exceed the IC’s package power dissipation limits.
Typical Operating Characteristics
(V = V
PV
= 5V, V = 5V, T = +25°C, unless otherwise noted.)
EN A
PV1
EFFICIENCY vs. LOAD CURRENT (SKIP)
EFFICIENCY vs. LOAD CURRENT (PWM)
EFFICIENCY vs. LOAD CURRENT (PWM)
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
f
= 2.2MHz, PWM MODE
= 5V
f
= 2.2MHz, PWM MODE
V = 3.3V
IN
V
= 5V
SW
SW
IN
V
IN
V
= 3.3V
OUT
V
= 2.5V
OUT
V
= 3.3V
OUT
V
= 1.8V
OUT
V
= 1.2V
OUT
V
= 1.8V
V
= 1.8V
OUT
OUT
V
= 1.2V
0.1
OUT
V
= 1.2V
OUT
f
= 2.2MHz, SKIP MODE
SW
0
0.001
0.01
0.1
1
10
0.001
0.01
1.0
10
0.001
0.01
0.1
LOAD CURRENT (A)
1.0
10
LOAD CURRENT (A)
LOAD CURRENT (A)
Maxim Integrated
4
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
V
LOAD REGULATION (PWM)
V
LOAD REGULATION (SKIP)
EFFICIENCY vs. LOAD CURRENT (SKIP)
OUT
OUT
3.32
3.30
3.28
3.26
3.24
3.22
3.20
3.34
3.32
3.30
3.28
3.26
3.24
3.22
3.20
100
V
= 3.3V
IN
V = 5V
V
= 5V
IN
SKIP MODE
IN
PWM MODE
T
A
= +25°C
90
80
70
60
50
40
30
20
10
0
T
A
= +25°C
T
V
= 1.8V
OUT
V
= 1.2V
OUT
V
= 2.5V
OUT
= +125°C
A
T
A
= +125°C
T
A
= -40°C
T
= -40°C
A
f
= 2.2MHz, SKIP MODE
SW
0
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
(A)
0
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
(A)
0.0001 0.0010
0.01
0.1
1.0
10
I
I
LOAD
LOAD CURRENT (A)
LOAD
V
OUT
vs. V (PWM)
I vs. V (SKIP)
PV PV
I
PV
vs. TEMPERATURE
PV
1.850
50
45
40
35
30
25
20
15
10
5
30
28
26
24
22
20
18
16
14
PWM MODE
V
= 5V
SKIP MODE
PV
SKIP MODE
SET TO PRESET
1.840
1.830
1.820
1.810
1.800
1.790
1.780
1.770
1.760
1.750
I
= 0A
LOAD
V
OUT
VOLTAGE OF 0.8V
T
A
= +125°C
T
A
= -40°C
T
= +25°C
A
T
= +25°C
4.0
A
T
= -40°C
5.0
A
T
A
= +125°C
0
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
(V)
2.5
3.0
3.5
4.5
5.5
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
V
V
(V)
PV
PV
SHUTDOWN CURRENT vs. V
f
vs. TEMPERATURE
LOAD-TRANSIENT RESPONSE
IN PWM MODE
PV
SW
1000
100
10
2.20
2.18
2.16
2.14
2.12
2.10
2.08
2.06
2.04
2.02
2.00
MAX16962 toc10
V
= 5V
IN
PWM MODE
T
A
= +125°C
4A
1
0.5A
0A
I
LOAD
0.1
T
A
= +25°C
V
OUT
100mV/div
0.01
0.001
AC-COUPLED
T
= -40°C
4.5
A
2.5
3.0
3.5
4.0
(V)
5.0
5.5
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
100µs/div
V
PV
Maxim Integrated
5
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Pin Configurations
TOP VIEW
TOP VIEW
12
11
10
9
+
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
GND
PV2
GND
GND
PG
8
7
6
5
GND 13
GND 14
LX2
PV
PGND2
PGND1
LX1
SYNC
PWM
GND
OUTS
EN
MAX16962
MAX16962
GND
PV2
15
16
PV1
PG
EP
EP
PV1
+
EN
OUTS
1
2
3
4
TSSOP
TQFN
(4mm x 4mm)
Pin Descriptions
PIN
NAME
FUNCTION
Switching Node 2. LX2 is high impedance when the converter is off.
TQFN
TSSOP
1
2
3
4
3
4
5
6
LX2
PGND2 Power Ground 2
PGND1 Power Ground 1
LX1
Switching Node 1. LX1 is high impedance when the converter is off.
Input Supply 1. Bypass PV1 with at least a 4.7FF ceramic capacitor to PGND1. Connect PV1 to
PV2 for normal operation.
5
6
7
7
8
9
PV1
EN
Enable Input. Drive EN high to enable converter. Drive EN low to disable converter.
Feedback Input (Adjustable Output Option Only). Connect an external resistive divider from
VOUT to OUTS and GND to set the output voltage. See Figure 2.
OUTS
Power-Good Output. Open-drain output. PG asserts when VOUT drops below 8% or rises above
10% of the nominal output voltage. Connect to a 20kI pullup resistor.
8
10
PG
9,
13–15
1, 11,
15, 16
GND
PWM
Ground
PWM Control Input. Drive PWM high to put converters in forced-PWM mode. Drive PWM low to
put converters in SKIP mode.
10
11
12
13
Factory-Set Sync Input or Output. As an input, SYNC accepts a 1.7MHz to 2.4MHz external clock
signal. As an output, SYNC outputs a 90° phase-shifted signal with respect to internal oscillator.
SYNC
Maxim Integrated
6
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Pin Descriptions (continued)
PIN
NAME
PV
FUNCTION
TQFN
TSSOP
Device Supply Voltage Input. Bypass with at least a 1FF ceramic capacitor to GND. In addition,
connect a 10I decoupling resistor between PV and the bypass capacitor.
12
14
Input Supply 2. Bypass PV2 with at least a 4.7FF ceramic capacitor to PGND2. Connect PV2 to
PV1 for normal operation.
16
—
2
PV2
EP
Exposed Pad. Connect EP to a large-area contiguous copper ground plane for effective power
dissipation. Do not use as the only IC ground connection. EP must be connected to GND.
—
Soft-Start
Detailed Description
The MAX16962 includes an 8ms fixed soft-start time.
Soft-start time limits startup inrush current by forcing the
output voltage to ramp up over time towards its regula-
tion point.
The MAX16962 is a high-efficiency, synchronous step-
down converter that operates with a 2.7V to 5.5V input
voltage range and provides a 0.8V to 3.6V output voltage
range. The MAX16962 delivers up to 4A of load current
and achieves -3.7%/+2.6% output error over load, line,
and temperature ranges.
Spread-Spectrum Option
The MAX16962 featuring spread-spectrum (SS) opera-
tion varies the internal operating frequency up by
SS = 6% relative to the internally generated operating
frequency of 2.2MHz (typ). This function does not apply
to externally applied oscillation frequency. The internal
oscillator is frequency modulated with a 6% frequency
deviation. See the Selector Guide for available options.
The PWM input forces the MAX16962 into either a fixed-
frequency, 2.2MHz PWM mode or a low-power pulse
frequency modulation mode (SKIP). Optional spread-
spectrum frequency modulation minimizes radiated elec-
tromagnetic emissions due to the switching frequency.
The factory programmable synchronization I/O (SYNC)
enables system synchronization.
Synchronization (SYNC)
SYNC is a factory-programmable I/O. See the Selector
Guide for available options. When SYNC is configured
as an input, a logic-high on PWM enables SYNC to
Integrated low R
switches help improve efficiency
at heavy loads and make the layout a much simpler task
with respect to discrete solutions.
DSON
accept signal frequency in the range of 1.7MHz < f
SYNC
The device is offered with factory-preset output volt-
ages that achieve -3.7%/+2.6% output voltage accuracy
without using external resistors. In addition, the output
voltage can be set to any desired values between 0.8V
to 3.6V using an external resistive divider wth the adjust-
able option.
< 2.4MHz. When SYNC is configured as an output, a
logic-high on PWM enables SYNC to output a 90Nphase-
shifted signal with respect to internal oscillator.
Current-Limit/Short-Circuit Protection
The MAX16962 features current limit that protects the
device against short-circuit and overload conditions at
the output. In the event of a short-circuit or overload
condition, the high-side MOSFET remains on until the
inductor current reaches the high-side MOSFET’s cur-
rent-limit threshold. The converter then turns on the low-
side MOSFET to allow the inductor current to ramp down.
Once the inductor current crosses the low-side MOSFET
current-limit threshold, the converter turns on the high-
side MOSFET for minimum on-time periode. This cycle
repeats until the short or overload condition is removed.
Additional features include 8ms soft-start, 16ms power-
good delay output, overcurrent, and overtemperature
protections. See Figure 1.
Power-Good Output
The MAX16962 features an open-drain power-good out-
put that asserts when the output voltage drops 8% below
or rises 10% above the regulated voltage. PG remains
asserted for a fixed 16ms timeout period after the output
rises up to its regulated voltage. Connect PG to OUTS
with a 20kI resistor.
Maxim Integrated
7
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
CURRENT-SENSE
PV1
AMP
PV
MAX16962
SKIP CURRENT
PV2
COMP
PV1
CLK
PEAK CURRENT
LX1
RAMP
GENERATOR
COMP
PGND
PV
CONTROL
LOGIC
STEP-DOWN
LX2
Σ
PMW
COMP
PWM
PGND2
PGND1
PGND
V
REF
ERROR
AMP
ZERO-CROSSING
COMP
FPWM CLK
SOFT-START
GENERATOR
CURRENT LIM
COMP
POWER-GOOD
COMP
P1-OK
FEEDBACK
DRIVER
OUTS
SYNC
CLK
OSC.
MAIN
OTP
TRIM BITS
FPWM
VOLTAGE
REFERENCE
TH-SD
V
REF
PG
P1-OK
CONTROL
LOGIC
EN
GND
Figure 1. Internal Block Diagram
switch only when needed to maintain regulation. As such,
the converter does not switch MOSFETs on and off as
often as is the case in the FPWM mode. Consequently,
the gate charge and switching losses are much lower in
SKIP mode.
FPWM/SKIP Modes
The MAX16962 features an input (PWM) that puts the
converter either in SKIP mode or forced-PWM (FPWM)
mode of operation. See the Pin Descriptions for mode
detail. In FPWM mode, the converter switches at a con-
stant frequency with variable on-time. In skip mode, the
converter’s switching frequency is load-dependent until
the output load reaches the SKIP threshold. At higher
load current, the switching frequency does not change
and the operating mode is similar to the FPWM mode.
SKIP mode helps improve efficiency in light-load applica-
tions by allowing the converters to turn on the high-side
Overtemperature Protection
Thermal overload protection limits the total power dissi-
pation in the MAX16962. When the junction temperature
exceeds +165°C (typ), an internal thermal sensor shuts
down the internal bias regulator and the step-down con-
troller, allowing the IC to cool. The thermal sensor turns on
the IC again after the junction temperature cools by 15°C.
Maxim Integrated
8
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Table 1. Inductor Values vs. (V - V
)
IN
OUT
V
- V
(V)
5.0 to 3.3
0.8
5.0 to 2.5
0.6
5.0 to 1.5
0.47
3.3 to 0.8
0.33
IN
OUT
INDUCTOR (µH)
Inductor Selection
Three key inductor parameters must be specified for
operation with the MAX16962: inductance value (L),
V
OUT
inductor saturation current (I
), and DC resistance
SAT
R1
R2
C1
(R
). Use the following formulas to determine the
DCR
MAX16962
OUTS
minimum inductor value:
V
3
OUT_
L
=
V
− V
×(
)×(
)
(
)
MIN1
IN OUT_
V
f × 4A
OP
IN
where f
is the operating frequency. This value is
OP
2.2MHz unless externally synchronized to a different
frequency.
Figure 2. Adjustable Output Voltage Setting
The next equation ensures that the inductor curent
downslope is less than the internal slope compensation.
For this to be the case, the following equation needs to
be satisfied:
Applications Information
m2
2
− m ≥
Setting the Output Voltage
OUT
voltage.(See the Selector Guide.) To set the output to
Connect OUTS to V
for factory programmed output
where m2 is the inductor current downslope:
other voltages between 0.8V and 3.6V, connect a resis-
VOUT_
L
tive divider from output (V ) to OUTS to GND (Figure
OUT
2). Select R2 (OUTS to GND resistor) less than or equal
to 100kI. Calculate R1 (V
following equation:
to OUTS resistor) with the
OUT
and -m is the slope compensation:
0.8xIMAX
V
OUT
µs
R1 = R2
−1
V
OUTS
Solving for L:
R1×R2
R1+ R2
where
≤ 7.5kΩ
µs
1.6 × 4A
L
= V
×
MIN2
OUT
where V
table).
= 800mV (see the Electrical Characteristics
OUTS
The equation that provides the bigger inductor value
must be chosen for proper operation:
The external feedback resistive divider must be frequency
compensated for proper operation. Place a capacitor
across each resistor in the resistive divider network.
Use the following equation to determine the value of the
capacitors:
L
MIN
= max(L
, L
)
MIN1 MIN2
The maximum inductor value recommended is twice the
chosen value from the above formula.
R2
R1
L
= 2 x L
MIN
MAX
C1 = 10pF
Maxim Integrated
9
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Input Capacitor
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
ripple on the input caused by the circuit’s switching.
Output Capacitor
The minimum capacitor required depends on output
voltage, maximum device current capability, and the
error-amplifier voltage gain. Use the following formula to
determine the required output capacitor value:
The input capacitor RMS current requirement (I
defined by the following equation:
) is
RMS
V
x G
EAMP
V
(V
− V
)
REF
OUT PV1
OUT
C
=
OUT(MIN)
I
= I
RMS LOAD(MAX)
2π × f
× V
×R
CO
OUT CS
V
PV1
0.8V x 31.7
2π × 210kHz × V
=
I
has a maximum value when the input voltage
RMS
139mΩ
OUT ×
equals twice the output voltage (V
I
= 2V
), so
OUT
PV1
= I
/2.
RMS(MAX)
LOAD(MAX)
where f , the target crossover frequency, is 210kHz,
CO
Choose an input capacitor that exhibits less than +10NC
self-heating temperature rise at the RMS input current for
optimal long-term reliability.
G
R
, the error-amplifier voltage gain, is 31.7V/V, and
is 139mΩ.
EAMP
CS
The input-voltage ripple is composed of DV (caused
PCB Layout Guidelines
Q
by the capacitor discharge) and DV
(caused by the
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation. Use a multilayer
board whenever possible for better noise immunity and
power dissipation. Follow these guidelines for good PCB
layout:
ESR
ESR of the capacitor). Use low-ESR ceramic capacitors
with high-ripple current capability at the input. Assume
the contribution from the ESR and capacitor discharge
equal to 50%. Calculate the input capacitance and ESR
required for a specified input voltage ripple using the fol-
lowing equations:
1) Use a large contiguous copper plane under the
MAX16962 package. Ensure that all heat-dissipating
components have adequate cooling. The bottom
pad of the MAX16962 must be soldered down to
this copper plane for effective heat dissipation and
maximizing the full power out of the MAX16962. Use
multiple vias or a single large via in this plane for
heat dissipation.
∆V
ESR
ESR
=
IN
∆I
L
I
+
OUT
2
where:
and:
(V
− V
)× V
OUT
×L
PV1
V
OUT
× f
∆I
=
L
PV1 SW
2) Isolate the power components and high current path
from the sensitive analog circuitry. This is essential to
prevent any noise coupling into the analog signals.
I
×D(1− D)
V
OUT
V
OUT
C
=
and D =
IN
∆V × f
Q
SW
PV1
3) Add small footprint blocking capacitors with low
self-resonance frequency close to PV1, PV2, and PV.
where I
duty cycle.
is the maximum output current, and D is the
OUT
4) Keep the high-current paths short, especially at the
ground terminals. This practice is essential for stable,
jitter-free operation. The high current path composed
of input capacitors at PV1, PV2, inductor, and the
output capacitor should be as short as possible.
It is strongly recommended that a 4.7FF small footprint
be placed close to PV1 and PV2 and a minimum of 100nF
small footprint be placed close to PV. Using a small
footprint such as 0805 or smaller helps to reduce the total
parasitic inductance.
Maxim Integrated
10
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
5) Keep the power traces and load connections short.
7) The ground connection for the analog and power
section should be close to the IC. This keeps the
ground current loops to a minimum. In cases where
only one ground is used enough isolation between
analog return signals and high power signals must be
maintained.
This practice is essential for high efficiency. Use
thick copper PCBs (2oz vs. 1oz) to enhance full-load
efficiency.
6) OUTS are sensitive to noise for devices with external
feedback option. The resistive network, R1, R2, and
C1 must be placed close to OUTS and far away from
the LX_ node and high switching current paths. The
ground node of R2 must be close to GND.
Chip Information
Package Information
For the latest package outline information and land patterns (foot-
prints), go to www.maximintegrated.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PROCESS: BiCMOS
PACKAGE
TYPE
PACKAGE OUTLINE
LAND
PATTERN NO.
CODE
T1644+4
U16E+3
NO.
16 TQFN-EP
16 TSSOP-EP
21-0139
21-0108
90-0070
90-0120
Maxim Integrated
11
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Selector Guide
PACKAGE
SUFFIX
OUTPUT
VOLTAGE
SPREAD
SPECTRUM
ROOT PART
OPTION SUFFIX
SYNC IN/OUT
MAX16962
MAX16962
MAX16962
MAX16962
RAUE
SAUE
RATE
SATE
A/V+
A/V+
A/V+
A/V+
Ext. Adj.
Ext. Adj.
Ext. Adj.
Ext. Adj.
Disabled
Enabled
Disabled
Enabled
In
In
In
In
Note: Contact the factory for variants with different output-voltage, spread-spectrum , and power-good delay time settings.
Ordering Information
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
LOAD CURRENT CAPABILITY (A)
PIN-PACKAGE
16 TQFN-EP*
16 TSSOP-EP*
MAX16962_ATE_/V+
MAX16962_AUE_/V+
4
4
Note: “_” is a package suffix placeholder for either “R” or “S,” as shown the Selector Guide. The second “_” is in the option suffix.
/V denotes an automotive qualified part.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Maxim Integrated
12
MAX16962
4A, 2.2MHz, Synchronous Step-Down
DC-DC Converter
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
7/12
Initial release
—
Updated Electrical Characteristics table, TOCs 1, 2, and 4, equation in the Setting
the Output Voltage section, step 6 in the PCB Layout Guidelines, and the Ordering
Information section
1
9/13
3–5, 9–11
Added FB regulation voltage specifications and updated V condition in Electrical
PV
2
3
5/14
7/15
Characteristics table; corrected equations and updated Table 2 in the Inductor
Selection and Output Capacitor sections; updated Ordering Information
2, 3, 9–11
Added formula to equation in the Setting the Output Voltage section, replaced the
Output Capacitor section, and deleted Table 2
9, 10
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent
licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and
max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
13
©
2014 Maxim Integrated Products, Inc.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
相关型号：
MAX16970
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16970GEEA/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16970GEEB/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16970GTEB/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16971
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16971GEEA/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16971GEEB/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
MAX16971GTEB/V+
3A Automotive Hi-Speed USB Protectors with Apple iPhone/iPad and USB 2.0 Charge Detection
MAXIM
©2020 ICPDF网 联系我们和版权申明