4
FN6474.1
February 22, 2008
FEEDBACK INPUTS
Vref
FB
Input Reference Voltage on FB T
A
= +25°C 1.13 1.15 1.17 V
T
A
= -40°C to +85°C 1.12 1.15 1.18 V
I
FB
Input Current in FB FB = 1.3V -0.2 0.2 µA
R
FB
FB Pull-Down Switch Resistance I
FB
= 10mA 15 25
SYNCHRONIZATION INPUT – NSYNC
f
NSYNC
External Sync Frequency Range 600 1400 kHz
td
NSYNC
NSYNC Falling Edge to LX Falling Edge
Delay
f
NSYNC
= 600kHz 80 100 ns
OVERVOLTAGE DETECTOR - V
OUT
V
OUT
Overvoltage Threshold FB = GND 31 35 V
OVERCURRENT DETECTOR
I
OCTVDDOUT
Overcurrent Threshold t > 2.048ms, DC current 800 mA
OVER-TEMPERATURE DETECTOR
t
OFF
Shut-Down Temperature Threshold T rising 135 °C
t
ON
Turn-On Temperature Threshold T falling 100 °C
FAULT SWITCH – VDD, VDDOUT
r
ONFS
ON-Resistance from VDD to VDDOUT I
OUT
= 50mA, t > 2.048ms 0.2
Ileak
VDDOUT
Leakage Current V
DDOUT
= 0V 0.01 3 µA
I
SS_VDDOUT
Soft Inrush Current Source at VDDOUT V
DD
- V
DDOUT
= 0.5V, t
ON
< 2.048ms 50 mA
REGULATION
ACC Output Voltage Accuracy, Assuming
Resistor Divider Tolerances of 0.1% or
Better
I
OUT
= 10mA, T
A
= +25°C -1.5 1.5 %
I
OUT
= 10mA, T
A
= -40°C to +85°C -2.5 2.5 %
V
OUT
/I
OUT
Load Regulation I
OUT
= 0mA to 50mA 0.05 %
V
OUT
/V
DD
Line Regulation V
DD
= 3.6V to 2.6V, I
OUT
= 30mA 0.1 %/V
Electrical Specifications V
DD
= 3.6V, GND = NEN = 0V, NSYNC = V
DD
, R
1
= 390k, R
2
= 39k, L = 10µH, T
A
= -40°C to +85°C unless
otherwise stated. (Continued)
PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT
ISL97701
