SS9175/6
Dual Synchronous DC/DC Controllers With Current Sharing Circuitry
FEATURES
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)
DESCRIPTION
The SS9175/6 series are dual-phase synchronous
DC/ DC PW M co ntrol l ers for po wer su ppl i e s
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.
The SS9175CS is a 20-pin version designed for
current sharing applications.
The SS9176CS is a 16-pin version for current
sharing applications
.
APPLICATIONS
n
n
n
n
CPU and DSP Vcore Power Supply
Graphic cards
Telecomm and datacomm POL boards
Power supplies requiring two independent outputs
TYPICAL APPLICATION CIRCUIT
PWRG
1.4v
5V
12V
2.2pF
1uF
1k
7.5uH
PWRG
IN1
COM
VCC
CL1+
CL1-
BST1
DH1
DL1
PGND
GND
IN2
COM
SS/ENB
CL2+
CL2-
BST2
DH2
DL2
BSTC
1k
1uF
7.5uH
50k
10uF
450uF
50k
0.22uF
Rev.2.02 12/29/2003
PRELIMINARY
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SS9175/6
ORDERING INFORMATION
SS917x xx-xx xx
Packing:
TR tape and reel: TB tubes
Fixed operating frequency:
3/6/10 for 300/600/1000kHz
Configuration:
CS = current sharing; blank = independent outputs (9175 only)
Part/package type:
9175 is in SO-20; 9176 is in SO-16
Examples: SS9176CS-10TR
SS9176 with current-sharing outputs, 1000kHz in SO-16 on tape and reel
SS9175-6TR
SS9175 with independent outputs, 600kHz in SO-20 on tape and reel
MARKING INFORMATION
20
16
SS9175UU-H
XXXXXXXYYWWV
SS9176CS-H
XXXXXXXYYWWV
1
UU:
= SS9175
UU: CS = SS9175CS
H : 3, 6 or 10
XXXXXXX: Wafer Lot
YY: Year; WW: Week
V: Assembly Location
1
H : 3, 6 or 10
XXXXXXX: Wafer Lot
YY: Year; WW: Week
V: Assembly Location
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SS9175/6
ABSOLUTE MAXIMUM RATINGS
Symbol
Vcc
PGND
VBST
RT j-a
T
J
T
A
Tstg
Parameter
Supply voltage, VCC to GND
PGND to GND
BST to PGND
Thermal resistance, Junction-air
Operating junction temperature
Operating ambient temperature
Storage temperature range
ESD Capability, HBM model
ESD Capability, Machine model
Test Condition
Low impedance source
Value
20
± 0.7
30
90
-40 to +125
-30 to +85
-65 to +150
2.0
200
Unit
V
V
V
°C/W
°C
°C
°C
kV
V
-
-
-
RECOMMENDED OPERATING CONDITIONS
Symbol
VCC
T
A
Parameter
Supply voltage
Operating ambient temperature
Min.
4.5
0
Max.
16
70
Unit
V
°C
ELECTRICAL CHARACTERISTICS
(V
CC
=12V, T
a
=25°C)
Oscillator Section
Symbol
Fosc-3
Fosc-6
Fosc-10
fdv
fdt
DC
Max
Parameter
Oscillator frequency -3 version
Oscillator frequency -6 version
Oscillator frequency -10 version
Frequency change with VCC
Frequency change with temp.
Maximum duty cycle
Test Condition
Ta=25°C
Ta=25°C
Ta=25°C
VCC=4.5 to 16V
Ta=0 to 70°C
Min.
270
550
920
-
-
85
Typ.
300
600
1000
0.2
0.02
95
Max.
330
650
1080
-
Unit
KHz
KHz
KHz
%
%/°C
%
Error Amplifier Section
Symbol
Vref
Avol
BW
PSRR
Isource
Isink
V
H COMP
V
L COMP
Parameter
Internal reference voltage
Open-loop voltage gain
Unity gain bandwidth
Power supply rejection ratio
Output source current
Output sink current
Output voltage
Output voltage
Test Condition
Ta=25°C
-
-
-
Min.
0.693
45
0.7
50
Typ.
0.7
55
1.2
-
Max.
0.707
-
-
-
Unit
V
dB
MHz
dB
mA
mA
V
mV
Output Section
Symbol
Tr
Tf
I
DH, CH
I
DH, DIS
Parameter
Rising time
Falling time
High side source current
High side sink current
Test Condition
Ta=25°C, CL=10nF
Ta=25°C, CL=10nF
Min.
-
-
1
1
Typ.
20
20
Max.
50
50
Unit
nS
nS
A
A
Total Operating Current Section
Symbol
I
CC OP
I
CC SBY
Parameter
Operating supply current
Standby current (disabled)
Test Condition
VCC=12V, OUTPUT=1000pF
Min.
-
Typ.
5.0
0.5
Max.
Unit
mA
mA
Rev.2.02 12/29/2003
PRELIMINARY
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