sc1146csw.tr Semtech Corporation, sc1146csw.tr Datasheet - Page 4

• Manufacturer Part Number: sc1146csw.tr
• Description: Vrm9.0 Programmable, Multi-phase, High Performance Pwm Controller
• Manufacturer: Semtech Corporation

July 25, 2000
PIN DESCRIPTION
NOTE: (1) All logic inputs and outputs are open collector TTL compatible.
The SC1146 is patent pending
© 2000 SEMTECH CORP.
Pin #
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1
2
3
4
5
6
7
8
9
V
Divsel
Clksel
Extclk
R
VID0
VID1
VID2
VID3
VID4
OC+
OC-
COMP
FB
BG
FBG
ENABLE
GND
DRV2
DRV0
VCC2
DRV1
DRV3
PWRGOOD
CC 5V
REF
OUT
(1)
(1)
(1)
(1)
(1)
Pin Name
Supply voltage input (5V nominal)
operation.
clock.
External Clock Input. The output frequency is determined by (Clock Input
Freq.)/4. Output freq.= (Clock Input)/4. Pull up to Vcc5v to select internal
clock.
Connects to external reference resistor. Sets the operating frequency of
the internal clock and the ramp time for the PWM. Reference voltage at
this pin is 2.05V. Trimmed to set 250µA at 8MHz.
Programming Input (LSB)
Programming Input
Programming Input
Programming Input
Programming Input (MSB)
Over current comparator. Non-Inverting input.
Over current comparator. Inverting input.
Compensation Pin. Compensation is acheived by connecting a capacitor in
series with a resistor between this pin and FBG. A 300K ohm resistor
must also be directly connected between this pin and FBG.
Feedback input connected to supply output.
Bandgap Reference Output. Output resistance = 3Kohm. Must be
bypassed with 4.7nF-100nF capacitor to FBG. This capacitor programs the
soft start time.
Feedback Ground. This pin must be connected to return side of output
caps. This pin is not internally connected to GND.
Ground Pin
Phase 2 output, output voltage range ~.3V - V
Phase 0 output, output voltage range ~.3V - V
Supply voltage for the DRV0-3, may be connected to +5V or +12V supply.
There is no Undervoltage Lockout on this pin.
Phase 1 output, output voltage range ~.3V - V
Phase 3 output, output voltage range ~.3V - V
Power good should be pulled-up to 5V supply via a 3K - 10K resistor.
Pin Function
Connect to Gnd for four phase operation and to logic High for three Phase
Clock Select: Logic High selects internal clock. Logic Low selects external
Connects to 5V to ENABLE. Connect to GND to disable entire device.
VRM9.0 PROGRAMMABLE, MULTI-PHASE,
HIGH PERFORMANCE PWM CONTROLLER
652 MITCHELL ROAD NEWBURY PARK CA 91320
CC2
CC2
CC2
CC2
- 1V.
- 1V.
- 1V.
- 1V.
SC1146
4