MAX1632AEAI Datasheet, PDF (6/29 Pages) Maxim Integrated Products – Multi-Output, Low-Noise Power-Supply Controllers for Notebook Computers

Multi-Output, Low-Noise Power-Supply
Controllers for Notebook Computers
____________________________________Typical Operating Characteristics (continued)
(Circuit of Figure 1, 3A Table 1 components, T_A = +25°C, unless otherwise noted.)
SWITCHING FREQUENCY
vs. LOAD CURRENT
1000
VL REGULATOR OUTPUT VOLTAGE
vs. OUTPUT CURRENT
5.00
100
+5V, V_IN = 15V
10 +3.3V, V_IN = 15V
1
0.1
0.1
+3.3V, V_IN = 6V
+5V, V_IN = 6V
1
10
100
1000
LOAD CURRENT (mA)
4.98
4.96
4.94
4.92
V_IN = 15V
ON3 = ON5 = 0V
4.90
0 10 20 30 40 50 60
OUTPUT CURRENT (mA)
REF OUTPUT VOLTAGE
vs. OUTPUT CURRENT
2.510
2.505
RUN
5V/div
STARTUP WAVEFORMS
2.500
2.495
2.490
2.485
V_IN = 15V
ON3 = ON5 = 0V
2.480
01
2
3
4
5
6
OUTPUT CURRENT (mA)
3.3V OUTPUT
2V/div
TIME
5V/div
5V OUTPUT
5V/div
2ms/div
SEQ = VL, 0.015μF CAPACITOR ON-TIME
__________________________________________________________________________Pin Description
PIN
NAME
FUNCTION
1
CSH3
Current-Sense Input for the 3.3V SMPS. Current-limit level is 100mV referred to CSL3.
2
CSL3
Current-Sense Input. Also serves as the feedback input in fixed-output mode.
Feedback Input for the 3.3V SMPS; regulates at FB3 = REF (approx. 2.5V) in adjustable mode. FB3 is a
3
FB3
Dual Mode input that also selects the 3.3V fixed output voltage setting when tied to GND. Connect FB3
to a resistor-divider for adjustable-output mode.
12OUT
(MAX1630A/
32A/33A/35A)
12V/120mA Linear Regulator Output. Input supply comes from V_DD. Bypass 12OUT to GND with
1µF minimum.
4
STEER
(MAX1631A/
MAX1634A)
Logic-Control Input for secondary feedback. Selects the PWM that uses a transformer and secondary
feedback signal (SECFB):
STEER = GND: 3.3V SMPS uses transformer
STEER = VL: 5V SMPS uses transformer
6 _______________________________________________________________________________________