isl6236a Intersil Corporation, isl6236a Datasheet - Page 8

• Manufacturer Part Number: isl6236a
• Description: High-efficiency, Quad-output, Main Power Supply Controllers For Notebook Computers
• Manufacturer: Intersil Corporation

Pin Descriptions
Typical Performance Curves
100
FIGURE 1. V
90
80
70
60
50
40
30
20
10
PIN
0
22
23
24
25
26
27
28
29
30
31
32
0.001
7 V
7 V
7 V
12 V
12 V
IN
IN
IN
IN
IN
PHASE2
UGATE2
LGATE2
SKIP MODE
PWM MODE
ULTRA SKIP MODE
REFIN2
BOOT2
OUT2
NAME
PGND
SKIP#
SKIP MODE
PWM MODE
POK2
OUT2
ILIM2
EN2
0.010
= 1.05V EFFICIENCY vs LOAD (300kHz)
(Continued)
OUTPUT LOAD (A)
Power Ground for SMPS controller. Connect PGND externally to the underside of the exposed pad.
SMPS2 Synchronous-Rectifier Gate-Drive Output. LGATE2 swings between GND and PVCC.
Boost Flying Capacitor Connection for SMPS2. Connect to an external capacitor according to the “Typical Application
Circuits” on page 19 (Figure 66, Figure 67, and Figure ). See “MOSFET Gate Drivers (UGATE, LGATE )” on page 29.
Inductor Connection for SMPS2. PHASE2 is the internal lower supply rail for the UGATE2 high-side gate driver.
PHASE2 is the current-sense input for the SMPS2.
High-Side MOSFET Floating Gate-Driver Output for SMPS2. UGATE1 swings between PHASE2 and BOOT2.
SMPS2 Enable Input. The SMPS2 is enabled if EN2 is greater than the logic high level and disabled if EN2 is less than
the logic low level. If EN2 is connected to REF, the SMPS2 starts after the SMPS1 reaches regulation (delay start). Drive
EN2 below 0.8V to clear fault level and reset the fault latches.
SMP2 Power-Good Open-Drain Output. POK2 is low when the SMPS2 output voltage is more than 10% below the
normal regulation point or during soft-start. POK2 is high impedance when the output is in regulation and the soft-start
circuit has terminated. POK2 is low in shutdown.
Low-Noise Mode Control. Connect SKIP# to GND for normal Idle-Mode (pulse-skipping) operation or to VCC for PWM
mode (fixed frequency). Connect to REF or leave floating for ultrasonic skip mode operation.
SMPS2 Output Voltage-Sense Input. Connect to the SMPS2 output. OUT2 is an input to the Constant on-time-PWM
on-time one-shot circuit. It also serves as the SMPS2 feedback input in fixed-voltage mode.
SMPS2 Current-Limit Adjustment. The GND-PHASE1 current-limit threshold is 1/10th the voltage seen at ILIM2 over a
0.2V to 2V range. There is an internal 5µA current source from VCC to ILIM2. Connect ILIM2 to REF for a fixed 200mV.
The logic current limit threshold is default to 100mV value if ILIM2 is higher than VCC - 1V.
Output voltage control for SMPS2. Connect REFIN2 to VCC for fixed 3.3V. Connect REFIN2 to VREF3 for fixed 1.05V.
REFIN2 can be used to program SMPS2 output voltage from 0.5V to 2.50V. SMPS2 output voltage is 0V if
REFIN2 < 0.5V.
8
0.100
12 V
25 V
25 V
25 V
IN
IN
IN
IN
ULTRA SKIP MODE
SKIP MODE
PWM MODE
ULTRA SKIP MODE
1.000
Circuit of Figure 66, Figure 67, and Figure , no load on LDO, OUT1, OUT2, V
V
unless otherwise noted. Typical values are at T
IN
= 12V, EN2 = EN1 = VCC, V
10.000
ISL6236A
FUNCTION
100
FIGURE 2. V
BYP
90
80
70
60
50
40
30
20
10
0
0.001
= 5V, PVCC = 5V, V
7 V
7 V
7 V
12 V
12 V
IN
IN
IN
IN
IN
SKIP MODE
PWM MODE
ULTRA SKIP MODE
OUT1
A
SKIP MODE
PWM MODE
= +25°C.
0.010
= 1.5V EFFICIENCY vs LOAD (200kHz)
OUTPUT LOAD (A)
EN_LDO
0.100
= 5V, T
12 V
25 V
25 V
25 V
A
IN
IN
IN
IN
= -40°C to +100°C,
ULTRA SKIP MODE
SKIP MODE
PWM MODE
ULTRA SKIP MODE
REF3
1.000
, and REF,
June 28, 2007
FN6453.1
10.000