CS5157H
http://onsemi.com
5
ELECTRICAL CHARACTERISTICS (0°C < T
A
< +70°C; 0°C < T
J
< +125°C; 8.0 V < V
CC1
< 14 V; 5.0 V < V
CC2
< 20 V;DAC Code:
V
ID4
= V
ID2
= V
ID1
= V
ID0
= 1; V
ID3
= 0
;
CV
GATE(L)
and CV
GATE(H)
= 1.0 nF; C
OFF
= 330 pF; C
SS
= 0.1 mF, unless otherwise specified.)
Characteristic UnitMaxTypMinTest Conditions
Supply Current
I
CC1
No Switching − 8.5 13.5 mA
I
CC2
No Switching − 1.6 3.0 mA
Operating I
CC1
V
FB
= COMP = V
FFB
− 8.0 13 mA
Operating I
CC2
V
FB
= COMP = V
FFB
− 2.0 5.0 mA
C
OFF
Normal Charge Time V
FFB
= 1.5 V; V
SS
= 5.0 V 1.0 1.6 2.2
ms
Extension Charge Time V
SS
= V
FFB
= 0 5.0 8.0 11.0
ms
Discharge Current C
OFF
to 5.0 V; V
FB
> 1.0 V 5.0 − − mA
Time Out Timer
Time Out Time V
FB
= V
COMP
; V
FFB
= 2.0 V;
Record V
GATE(H)
Pulse High Duration
10 30 65
ms
Fault Mode Duty Cycle V
FFB
= 0V 35 50 70 %
PACKAGE PIN DESCRIPTION
PACKAGE PIN #
SOIC−16
1, 2, 3, 4, 6 V
ID0
−V
ID4
Voltage ID DAC input pins. These pins are internally pulled up to 5.0 V providing logic ones if left
open. V
ID4
selects the DAC range. When V
ID4
is High (logic one), the DAC range is 2.10 V to
3.50 V with 100 mV increments. When V
ID4
is Low (logic zero), the DAC range is 1.30 V to
2.05 V with 50 mV increments. V
ID0
− V
ID4
select the desired DAC output voltage. Leaving all
5 DAC input pins open results in a DAC output voltage of 1.2440 V, allowing for adjustable output
voltage, using a traditional resistor divider.
5 SS
Soft−Start Pin. A capacitor from this pin to LGND in conjunction with internal 60 mA current
source provides Soft−Start function for the controller. This pin disables fault detect function
during Soft−Start. When a fault is detected, the Soft−Start capacitor is slowly discharged by
internal 2.0 mA current source setting the time out before trying to restart the IC.
Charge/discharge current ratio of 30 sets the duty cycle for the IC when the regulator output is
shorted.
7 C
OFF
A capacitor from this pin to ground sets the time duration for the on board one shot, which is
used for the constant off time architecture.
8 V
FFB
Fast feedback connection to the PWM comparator. This pin is connected to the regulator output.
The inner feedback loop terminates on time.
9 V
CC2
Boosted power for the high side gate driver.
10 V
GATE(H)
High FET driver pin capable of 1.5 A peak switching current. Internal circuit prevents V
GATE(H)
and V
GATE(L)
from being in high state simultaneously.
11 PGND High current ground for the IC. The MOSFET driver is referenced to this pin. Input capacitor
ground and the source of lower FET should be tied to this pin.
12 V
GATE(L)
Low FET driver pin capable of 1.5 A peak switching current.
13 V
CC1
Input power for the IC and low side gate driver.
14 LGND Signal ground for the IC. All control circuits are referenced to this pin.
15 COMP Error amplifier compensation pin. A capacitor to ground should be provided externally to
compensate the amplifier.
16 V
FB
Error amplifier DC feedback input. This is the master voltage feedback which sets the output
voltage. This pin can be connected directly to the output or a remote sense trace.
