Rainbow Electronics MAX782 - Manual (Page 7)

MAX782
Triple-Output Power-Supply
Controller for Notebook Computers
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NAME FUNCTION
ON3 Logic input to turn on +3.3V. Logic high turns on the regulator. Connect to VL for automatic start-up.
D1
#1 level-translator/comparator noninverting input. Inverting comparator input is internally connected to
1.650V. Controls Q1. Connect to GND if unused.
D2
1
2
D3
VH
Q3
Q2
3
4
5
Q1
#1 level-translator/comparator output. Sources 20µA from VH when D1 is high. Sinks 500µA to GND
when D1 is low, even with VH = 0V.
VPPA 0V, 5V, 12V, Hi-Z PCMCIA VPP output. Sources up to 60mA. Controlled by DA0 and DA1.
6
7
8
9
______________________________________________________________Pin Description
PIN
VDD
15V flyback input (feedback). A weak shunt regulator conducts 3mA to GND when VDD exceeds 19V.
Also the supply input to the VPP regulators.
10
VPPB 0V, 5V, 12V, Hi-Z PCMCIA VPP output. Sources up to 60mA. Controlled by DB0 and DB1. 11
GND Low-current analog ground 12
Intel 82365 compatible PCMCIA VPP control inputs (see Table 1) 15-18
SYNC 14
REF 13
Oscillator frequency control and synchronization input: Connect to VL or to GND for f = 200kHz; connect
to REF for f = 300kHz. For external synchronization in the 240kHz to 350kHz range, a high-to-low transi-
tion causes the start of a new cycle.
DA1, DA0,
DB1, DB0
#2 level-translator/comparator output. Sources 20µA from VH when D2 is high. Sinks 500µA to GND
when D2 is low, even with VH = 0V.
#3 level-translator/comparator output. Sources 20µA from VH when D3 is high. Sinks 500µA to GND
when D3 is low, even with VH = 0V.
External supply input for level-translator/comparator. For N-channel FET drive, connect to VDD or external
+13V to +18V supply. For low-battery comparators, connect to +3.3V or +5V (or to VL/REF).
#3 level-translator/comparator noninverting input. Inverting comparator input is internally connected to
1.650V. Controls Q3. Connect to GND if unused.
#2 level-translator/comparator noninverting input. Inverting comparator input is internally connected to
1.650V. Controls Q2. Connect to GND if unused.
Logic input to turn on +5V. Logic high turns on the regulator. Connect to VL for automatic startup. 19 ON5
SS5 20
CS5
+5V-supply current-sense input. +100mV = current limit in buck mode, -100mV = current limit in flyback
mode (where the ±100mV are referenced to FB5).
21
DH5 +5V-supply external MOSFET high-side switch-drive output 22
+5V-supply soft-start control input. Ramp time to full current limit is 1ms/nF of capacitance to GND.
3.3V reference output. Sources up to 5mA for external loads. Bypass to GND with 1µF/mA load or
0.22µF minimum.
23 LX5 +5V-supply inductor connection