FAN5236 — Dual Mobile-Friendly DDR / Dual-Output PWM Controller
Pin Configuration
AGND
LDRV1
PGND1
SW1
HDRV1
BOOT1
ISNS1
EN1
FPWM1
VSEN1
ILIM1
SS1
DDR
VIN
1
2
3
4
5
6
28
27
26
25
24
23
VCC
LDRV2
PGND2
SW2
HDRV2
BOOT2
ISNS2
EN2
FPWM2
VSEN2
ILIM2/REF2
SS2
PG2/REF2OUT
PG1
7
22
FAN5236
8
21
9
10
11
12
13
14
20
19
18
17
16
15
Figure 3. Pin Configuration
Pin Definitions
Pin #
1
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
12
17
Name
AGND
LDRV1
LDRV2
PGND1
PGND2
SW1
SW2
HDRV1
HDRV2
BOOT1
BOOT2
ISNS1
ISNS2
EN1
EN2
FPWM1
FPWM2
VSEN1
VSEN2
ILIM1
SS1
SS2
Description
Analog Ground.
This is the signal ground reference for the IC. All voltage levels are
measured with respect to this pin.
Low-Side Drive.
The low-side (lower) MOSFET driver output. Connect to gate of low-side
MOSFET.
Power Ground.
The return for the low-side MOSFET driver. Connect to source of low-side
MOSFET.
Switching Node.
Return for the high-side MOSFET driver and a current sense input.
Connect to source of high-side MOSFET and low-side MOSFET drain.
High-Side Drive.
High-side (upper) MOSFET driver output. Connect to gate of high-side
MOSFET.
BOOT.
Positive supply for the upper MOSFET driver. Connect as shown in Figure 4.
Current-Sense Input.
Monitors the voltage drop across the lower MOSFET or external
sense resistor for current feedback.
Enable.
Enables operation when pulled to logic HIGH. Toggling EN resets the regulator
after a latched fault condition. These are CMOS inputs whose state is indeterminate if left
open.
Forced PWM Mode.
When logic LOW, inhibits the regulator from entering Hysteretic Mode;
otherwise tie to V
OUT
. The regulator uses V
OUT
on this pin to ensure a smooth transition from
Hysteretic Mode to PWM Mode. When V
OUT
is expected to exceed V
CC
, tie to V
CC
.
Output Voltage Sense.
The feedback from the outputs. Used for regulation as well as PG,
under-voltage, and over-voltage protection and monitoring.
Current Limit 1.
A resistor from this pin to GND sets the current limit.
Soft Start.
A capacitor from this pin to GND programs the slew rate of the converter during
initialization. During initialization, this pin is charged with a 5mA current source.
© 2002 Fairchild Semiconductor Corporation
FAN5236 • Rev. 1.3.2
www.fairchildsemi.com
3
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
