SM8172A Datasheet, PDF (1/17 Pages) Nippon Precision Circuits Inc – 2-output Power Supply IC

SM8172A
2-output Power Supply IC
1. OVERVIEW
The SM8172A is a 2-output power supply IC that incorporates a step-down DC/DC converter and series regu-
lator with built-in reset circuit. The DC/DC converter is a PWM-type synchronous rectifier. The SM8172A has
soft start, overcurrent detection, supply undervoltage lockout, and thermal shutdown circuits built-in, making it
ideal as a supply voltage source IC for large-scale LSIs that operate from a 5V supply.
2. FEATURES
I Input voltage range: 4.5 to 5.5V
I Standby current: 0.01µA (typ)
I Series regulator
• Feedback-type current limiter to reduce output
current when outputs are short-circuit
• Output voltage: 3.3V
(available for optional setting from 2.1 to 3.6V
by 0.1V-step)
• Maximum output current: 450mA
• Voltage accuracy: ± 2% (VIN = 5.0V, Ta = 25°C)
I DC/DC converter
• Current-mode operation for excellent transient
response
• Output voltage: 0.8 to 1.8V
(typ, selectable by external resistor)
• Maximum output current: 900mA
• Operating frequency: 2MHz (typ)
• Voltage accuracy: ± 2%
(FB pin, VIN = 5.0V, Ta = 25°C, DCOUT = 1.0V)
I Reset circuit built-in
• Reset detection voltage: 3.7V (typ)
(available for optional setting from 3.2 to 4.2V
by 0.1V-step)
• Reset return delay time: 65ms (typ)
(50ms, 32ms, 16ms, and 8ms selectable with
option)
I Various protection circuit built-in
• Startup soft start circuit built-in
• Overtemperature thermal shutdown (TSD) circuit
built-in
• Supply undervoltage lockout (UVLO) circuit
built-in
I Package: 10-pin SON
3. APPLICATIONS
I ODD
I DVD player/recorder
I Next-generation DVD player/recorder
I Electronic equipment
4. TYPICAL APPLICATION CIRCUIT
5.0V
C1
10µF
VIN1
PGND
RESETN
R3
10kΩ
RESETN output
C2
10µF
DC/DC control
Regulator control
VIN2
GND
ENDCO
ENLDO
LDOUT
FB
LX
C5
3.3µF
Regulator output
R2
330kΩ
C3
R1
8pF
220kΩ
L
2.2µH
C4
4.7µF
DCOUT
(1.0V)
Note. RESETN is open-drain, therefore, please take care so that the High level signal does not exceed the absolute maximum rating of IC which receives
the reset signal. Besides, if the rest signal is not used, RESETN should be connected to GND.
5. ORDERING INFORMATION
Device
SM8172AD
Package
10-pin SON
SEIKO NPC CORPORATION —1