MAX1540A Datasheet, PDF (20/49 Pages) Maxim Integrated Products – Dual Step-Down Controllers with Saturation Protection, Dynamic Output, and Linear Regulator

Dual Step-Down Controllers with Saturation
Protection, Dynamic Output, and Linear Regulator
PIN
MAX1540A MAX1541
31
39
32
40
—
—
Pin Description (continued)
NAME
ON2
ON1
EP
FUNCTION
OUT2 Enable Input. Pull ON2 to GND to shut down controller 2 (OUT2). Connect to
V_CC for normal operation. When discharge mode is enabled by OVP/UVP, the output
is discharged through a 10Ω resistor between OUT2 and GND, and DL2 is forced
high after V_OUT2 drops below 0.3V. When discharge mode is disabled by OVP/UVP,
OUT2 remains a high-impedance input and DL2 is forced low so LX2 also appears as
a high impedance. A rising edge on ON1 or ON2 clears the fault-protection latch.
OUT1 Enable Input. Pull ON1 to GND to shut down controller 1 (OUT1). Connect to
V_CC for normal operation. When discharge mode is enabled by OVP/UVP, the output
is discharged through a 10Ω resistor between OUT1 and GND, and DL1 is forced
high after V_OUT1 drops below 0.3V. When discharge mode is disabled by OVP/UVP,
OUT1 remains a high-impedance input and DL1 is forced low so LX1 also appears as
high impedance. A rising edge on ON1 or ON2 clears the fault-protection latch.
Exposed Backside Pad. Connect the exposed backside pad to analog ground.
Table 1. Component Selection for Standard Applications
COMPONENT
Input Voltage (V_IN)
Output Voltage (V_OUT_)
Load Current (I_OUT_)
Switching Frequency
( f_{S W}_)
Input Capacitor (C_IN)
PWM1
7V to 24V
1.8V
4A
MAX1540A
PWM2
7V to 24V
2.5V
8A
TON = REF (485kHz)
TON = REF (355kHz)
(2) 10µF, 25V
Taiyo Yuden TMK432BJ106KM
PWM1
7V to 24V
1.0V/1.5V
4A
MAX1541
PWM2
7V to 24V
2.5V
4A
TON = REF (485kHz)
TON = REF (355kHz)
(2) 4.7µF, 25V
Taiyo Yuden TMK325BJ475KM
Output Capacitor
(C_OUT_)
220µF, 6.3V, 12mΩ
Sanyo POSCAP
6TPD220M
330µF, 4V, 12mΩ
Sanyo POSCAP
4TPD330M
470µF, 4V, 10mΩ
Sanyo POSCAP
4TPD470M
220µF, 6.3V, 12mΩ
Sanyo POSCAP
6TPD220M
High-Side MOSFET
(N_H_)
Low-Side MOSFET
(N_L_)
Low-Side Schottky
(D_L_)
(if needed)
35mΩ, 30V
Fairchild 1/2 FDS6982S
22mΩ, 30V
Fairchild 1/2 FDS6982S
1A, 30V Schottky
Nihon EP10QS03L
20mΩ, 30V
Fairchild FDS6690
12.5mΩ, 30V
Fairchild FDS6670S
1A, 30V Schottky
Nihon EP10QS03L
35mΩ, 30V
Fairchild 1/2 FDS6982S
22mΩ, 30V
Fairchild 1/2 FDS6982S
35mΩ, 30V
Fairchild 1/2 FDS6982S
22mΩ, 30V
Fairchild 1/2 FDS6982S
1A, 30V Schottky
Nihon EP10QS03L
1A, 30V Schottky
Nihon EP10QS03L
Inductor (L_)
2.5µH, 6.2A, 15mΩ
Sumida
CDEP105(H)-2R5
2.2µH, 10A, 4.4mΩ
Sumida
CDEP105(L)-2R2
1.8µH, 9.0A, 6.2mΩ
Sumida
CDEP105(S)-1R8
4.3µH, 6.8A, 8.7mΩ
Sumida
CDEP105(L)-4R3
R_{SENSE_}
15mΩ ±1%, 0.5W
5mΩ ±1%, 0.5W
15mΩ ±1%, 0.5W
15mΩ ±1%, 0.5W
IRC LR2010-01-R015F IRC LR2010-01-R005F IRC LR2010-01-R015F IRC LR2010-01-R015F
or Dale WSL-2010-R015F or Dale WSL-2010-R005F or Dale WSL-2010-R015F or Dale WSL-2010-R015F
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