Rainbow Electronics MAX1635 - Manual (Page 4)

MAX1630–MAX1635
Multi-Output, Low-Noise Power-Supply
Controllers for Notebook Computers
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Note 1: Each of the four digital soft-start levels is tested for functionality; the steps are typically in 20mV increments.
Note 2: High duty-factor operation supports low input-to-output differential voltages, and is achieved at a lowered operating
frequency (see
Overload and Dropout Operation section).
Note 3: MAX1630/MAX1632/MAX1633/MAX1635 only.
Note 4: Off mode for the 12V linear regulator occurs when the SMPS that has flyback feedback (V DD ) steered to it is disabled. In
situations where the main outputs are being held up by external keep-alive supplies, turning off the 12OUT regulator pre-
vents a leakage path from the output-referred flyback winding, through the rectifier, and into V
DD .
Note 5: Since the reference uses VL as its supply, the reference’s V+ line-regulation error is insignificant.
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, both PWMs on, SYNC = VL, VL load = 0mA, REF load = 0mA, SKIP = 0V, T A = T MIN to T MAX , unless otherwise noted.
Typical values are at T A = +25°C.)
Typical hysteresis = +10°C
From each SMPS enabled, with respect to f OSC
°C 150
clks 5000 6144 7000
With respect to unloaded output voltage
Output Undervoltage Lockout Time
Thermal Shutdown Threshold
With respect to f OSC
Falling edge, CSL_ driven 2%
below RESET trip threshold
clks 27,000 32,000 37,000
µs 1.5
With respect to unloaded output voltage,
falling edge; typical hysteresis = 1%
RESET Propagation Delay
RESET Delay Time
% -7 -5.5 -4
CONDITIONS
RESET Trip Threshold
RESET, I
SINK = 4mA
RUN/ON3, SKIP, TIME/ON5 (SEQ = REF),
SHDN, STEER, SYNC, SEQ; V
PIN = 0V or 3.3V
V 0.4
µA ±1 Input Leakage Current
Logic Output Low Voltage
CSL_ driven 2% above overvoltage trip threshold µs
FB3, FB5; SECFB = 2.6V
1.5 Overvoltage-Fault Propagation Delay
nA 1 50
With respect to unloaded output voltage % 60 70 80
Feedback Input Leakage Current
Output Undervoltage Threshold
% 4 7 10 Overvoltage Trip Threshold
RUN/ON3, SKIP, TIME/ON5 (SEQ = REF),
SHDN, STEER, SYNC
RUN/ON3, SKIP, TIME/ON5 (SEQ = REF),
SHDN, STEER, SYNC
V 2.4
V 0.6 Logic Input Low Voltage
Logic Input High Voltage
UNITS MIN TYP MAX PARAMETER
High or low
DL3, DH3, DL5, DH5; forced to 2V
Ω
1.5 7
A 1 Gate Driver Sink/Source Current
Gate Driver On-Resistance
RESET = 3.5V mA 1 Logic Output High Current
TIME/ON5 = 0V, SEQ = 0V or VL
SEQ = 0V or VL
µA 2.5 3 3.5
V 2.4 2.6 TIME/ON5 Input Trip Level
TIME/ON5 Source Current
TIME/ON5; RUN/ON3 = 0V, SEQ = 0V or VL Ω 15 80 TIME/ON5 On-Resistance
FAULT DETECTION (MAX1630/MAX1631/MAX1632)
INPUTS AND OUTPUTS
RESET