MAX1634A

V+ to GND ..............................................................-0.3V to +36V
PGND to GND......................................................................±0.3V
VL to GND ................................................................-0.3V to +6V
BST3, BST5 to GND ................................................-0.3V to +36V
LX3 to BST3..............................................................-6V to +0.3V
LX5 to BST5..............................................................-6V to +0.3V
REF, SYNC, SEQ, STEER, SKIP, TIME/ON5,
SECFB, RESET to GND ..............................................-0.3V to +6V
VDD to GND............................................................-0.3V to +20V
RUN/ON3, SHDN to GND...............................-0.3V to (V+ + 0.3V)
12OUT to GND ...........................................-0.3V to (VDD + 0.3V)
DL3, DL5 to PGND.........................................-0.3V to (VL + 0.3V)
DH3 to LX3 ...............................................-0.3V to (BST3 + 0.3V)
DH5 to LX5 ...............................................-0.3V to (BST5 + 0.3V)
VL, REF Short to GND ................................................Momentary
12OUT Short to GND..................................................Continuous
REF Current...........................................................+5mA to -1mA
VL Current.........................................................................+50mA
12OUT Current ...............................................................+200mA
VDD Shunt Current............................................................+15mA
Operating Temperature Ranges
MAX163_ACAI ...........................................................0 to +70
MAX163_AEAI ........................................................-40 to +85
}Storage Temperature Range .............................-65 to +160
Continuous Power Dissipation (TA = +70°C)
SSOP (derate 9.52mW/°C above +70°C) ........ll............762mW
Lead Temperature (soldering, 10s) ..................................+300
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

The MAX1634A are buck-topology, stepdown, switch-mode, power-supply controllers that generate logic-supply voltages in battery-powered systems.

These high-performance, dual-/triple-output devices include on-board power-up sequencing, power-good signaling with delay, digital soft-start, secondary winding control, low-dropout circuitry, internal frequency-compensation networks, and automatic bootstrapping. Up to 96% efficiency is achieved through synchronous rectification and Maxim's proprietary Idle Mode™ control scheme. Efficiency is greater than 80% over a 1000:1 load-current range, which extends battery life in systemsuspend or standby mode. Excellent dynamic response corrects output load transients caused by the latest dynamic-clock CPUs within five 300kHz clock cycles. Strong 1A on-board gate drivers ensure fast external n-channel MOSFET switching.

These devices feature a logic-controlled and synchronizable, fixed-frequency, pulse-width-modulation (PWM) operating mode. This reduces noise and RF interference in sensitive mobile communications and pen-entry applications. Asserting the SKIP pin enables fixed-frequency mode for lowest noise under all load conditions.

The MAX1630AMAX1635A include two PWM regulators, adjustable from 2.5V to 5.5V with fixed 5.0V and 3.3V modes. All these devices include secondary feedback regulation, and the MAX1630A/MAX1632A/MAX1633A/ MAX1635A each contain 12V/120mA linear regulators.

The MAX1631A/MAX1634A include a secondary feedback input (SECFB), plus a control pin (STEER) that selects which PWM (3.3V or 5V) receives the secondary feedback signal. SECFB provides a method for adjusting the secondary winding voltage regulation point with an external resistor-divider, and is intended to aid in creating
auxiliary voltages other than fixed 12V.

The MAX1630A/MAX1631A/MAX1632A contain internal output overvoltage and undervoltage protection features. The MAX1630A family has improved RF immunity over the MAX1630 family.