PROGRAMMABLE, HIGH PERFORMANCE

MULTI-PHASE, PWM CONTROLLER

SC1144

© 1999 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA 91320

Preliminary - August 24, 1999

3

The SC1144 is patent pending

ELECTRICAL CHARACTERISTICS (Cont.)

Unless otherwise noted: T

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Bgout Voltage

V

Bgout

Vid = 00000

2.05

V

Bgout Impedance

R

O_Bg

3

K

Ω

External Clock Freq. Range

F

ext_CK

.80

8.0

8.5

MHz

Oscillator Frequency Accuracy

F

OSC

Iref = 250µA

7.2

8.0

8.8

MHz

Internal Clock Freq. Range

F

int_CK

.80

8.0

8.5

MHz

Match DRV0-3

∆

D

Duty cycle deviation from Avg.

-1

+1

%

PWM Off Time

Toff

25

%

Drive Voltage Range

OutV

Output Freq. = 2MHz/Phase

V

510

12

V

Overcurrent Comparator,

Comparator, Common Mode

Range

OCC_CMR

3

15

V

OC+I/P bias Current

IB_OC+

Vin = 5V,Roc+<20Kohm

+75

185

+250

µ

Α

OC-I/P bias Current

IB_OC-

Vin = 5V,Roc-<20Kohm

+75

125

+250

µ

Α

Input Offset Voltage

VOS_OCC

Vin = 5V

10

mV

Feedback Input Impedance

Ri_FB

V

12

ΚΩ

Maximum Duty Cycle

Dmax

FB=0V

75

%

Mimimum Duty Cycle

Dmin

FB=4.0V

0

%

CONVERTER SPECIFICATIONS, Reference Application Circuit

Output Accuracy Over Set

Range

V

OUT

VID 0-4 = 0000-1111

V

-1

+1

%

Load Regulation

V

I

.025

.05

%/A

Line Regulation

V

V

Vcc5v) I

.15

%/V

O

OUT

I

V

∆

∆

IN

OUT

V

V

∆

∆