SI9150 Datasheet, PDF (1/5 Pages) Vishay Siliconix – Synchronous Buck Converter Controller

Si9150
Vishay Siliconix
Synchronous Buck Converter Controller
FEATURES
D 6- to 16.5-V Input Range (Si9150CY)
D Voltage-Mode PWM Control
D Low-Current Standby Mode
D Enable Control
D Dual 100-mA Output Drivers
D 2% Band Gap Reference
D Multiple Converters Easily Synchronized
D Over-Current Protection
DESCRIPTION
The Si9150 synchronous buck regulator controller is ideally
suited for high-efficiency step down converters in
battery-powered equipment. Combined with the Si9943DY
MOSFET half-bridge, a 90% efficient, 7.5-W, 3.3-V or 5-V
power supply can be implemented using standard surface-
mount assembly techniques. The wide input range allows
operation from NiCd or NiMH battery packs using six to ten
cells.
Over-current protection is achieved by sensing the on-state
voltage drop across the high side p-channel MOSFET, which
eliminates the need for a current sense resistor.
Duty ratios of 0 to 100% and switching frequencies up to 300
kHz are possible. The IC can be disabled by pulling EN low
(I_DD = 100 mA), or the 2.5-V reference can be maintained, with
all other functions disabled, by pulling STBY low (I_DD =
500 mA).
The Si9150 is available in both standard and lead (Pb)-free
14-pin SOIC and rated for the commercial temperature range
of 0 to 70_C (C suffix), and the industrial temperature range of
−40 to +85_C (D suffix).
FUNCTIONAL BLOCK DIAGRAM
14
V_DD
1
EN
500 kW
20 mA
Power Down
0.5 V
UVLO
2
STBY
4.7 V
3
SS
Ref
Gen
5W
6
5
V_REF
FB
Document Number: 70020
S-40752—Rev. F, 19-Apr-04
R
Q
S
Oscillator,
Comparators,
& Error Amp
Reference
Generator
Current
Limit ₊
−
Strobe
Error
Amplifier
+
−
−
1V
+
OSC
R
Q
S
Break-
Before-
Make
Logic
4
COMP
9 10 8
C_T R_T SYNC
Synchronous Buck Regulator Controller
13
P-GATE
7
I_SENSE
V_DD
12
N-GATE
11
GND
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