SS9175/6
Dual Synchronous DC/DC Controllers With Current Sharing Circuitry
FEATURES
DESCRIPTION
Two sets of integrated MOSFET drivers
Fixed operating frequency of 300, 600 or 1000kHz
Dual-phase current-sharing controller to minimize
ripple and improve transient response
Wide input supply range: 4.5V to 16V
Programmable output as low as 0.8v
Internal error amplifier reference voltage of
0.7V +/- 1%
Programmable over-current protection (OCP) with
50% fold-back
Over-voltage protection (OVP)
Soft-start
Remote ON/OFF control
High voltage pin up to 30V for bootstrap voltage
Power-good output signal provided
Current-sharing balance within +/-5% matching
(SS9175CS/SS9176CS)
Two independent PWM controllers (SS9175)
Packaged in SO-20 (9175/CS) or SO-16 (9176CS)
The SS9175/6 series are dual-phase synchronous
DC/DC PWM controllers for power supplies
requiring a single high-current output, or two
independent outputs with high conversion efficiency.
They integrate two sets of internal MOSFET drivers
consisting of high-side and low side driving circuits.
The internal temperature-independent reference
voltage is trimmed to 0.7V +/- 1%, and is connected to
the error amplifier’s positive terminal for voltage
feedback regulation. The over-current protection
(OCP) level, with 50% fold-back, can be programmed
by an external resistor. The over-voltage protection
(OVP) point is fixed at 25% higher above 0.7V. The
soft-start circuit ensures the duty cycle of the PWM
output can be gradually and smoothly increased from
zero to its desired value. The controllers can be
remotely turned ON or OFF to enter into either active
or standby mode, respectively. The SS9175/6
series provides three different options:
The SS9175 is a 20-pin version that is designed for
two independent outputs without current sharing
capability.
APPLICATIONS
n
n
n
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CPU and DSP Vcore Power Supply
Graphic cards
Telecomm and datacomm POL boards
Power supplies requiring two independent outputs
The SS9175CS is a 20-pin version designed for
current sharing applications.
The SS9176CS is a 16-pin version for current
sharing applications.
TYPICAL APPLICATION CIRCUIT
PWRG
1.4v
5V
12V
GND
IN2
PWRG
IN1
COM
VCC
CL1+
CL1-
BST1
DH1
2.2pF
COM
1uF
1uF
SS/ENB
1k
1k
CL2+
CL2-
BST2
DH2
DL2
BSTC
DL1
PGND
7.5uH
7.5uH
50k
50k
10uF
450uF
0.22uF
Rev.2.02 12/29/2003 PRELIMINARY
www.SiliconStandard.com
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