The MAX1718 step-down controller is intended for core CPU DC-DC converters in notebook computers. It features a dynamically adjustable output, ultra-fast transient response, high DC accuracy, and high efficiency needed for leading-edge CPU core power supplies. Maxim's proprietary Quick-PWM™ quick-response, constant-ontime PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns "instant-on" response to load transients while maintaining a relatively constant switching frequency.
The output voltage can be dynamically adjusted through the 5-bit digital-to-analog converter (DAC) over a 0.6V to 1.75V range. The MAX1718 has an internal multiplexer that accepts three unique 5-bit VID DAC codes corresponding to Performance, Battery, and Suspend modes.Precision slew-rate control† provides "just-in-time" arrival at the new DAC setting, minimizing surge currents to and from the battery.
The internal DAC of the MAX1718B is synchronized to the slew-rate clock for improved operation under aggressive power management of newer chipsets and operating systems that can make incomplete mode transitions.
A pair of complementary offset control inputs allows easy compensation for IR drops in PC board traces or creation of a voltage-positioned power supply. Voltagepositioning modifies the load-transient response to reduce output capacitor requirements and total system power dissipation.
Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery) at a higher switching frequency allows the minimum possible physical size.
The MAX1718 is available in a 28-pin QSOP package.
V+ to GND ..............................................................-0.3V to +30V
VCC, VDD to GND ......................................................-0.3V to +6V
D0D4, ZMODE, VGATE,OVP, SUS, to GND ...............-0.3V to +6V
SKP/SDN to GND ....................................................-0.3V to +16V
ILIM, CC, REF, POS, NEG, S1, S0,
TON, TIME to GND......................................-0.3V to (VCC + 0.3V)
DL to GND..................................................-0.3V to (VDD + 0.3V)
BST to GND............................................................-0.3V to +36V
DH to LX ....................................................-0.3V to (BST + 0.3V)
LX to BST.................................................................-6V to +0.3V
REF Short Circuit to GND ..........................................Continuous
Continuous Power Dissipation
28-Pin QSOP (derate 10.8mW/°C above +70°C).............860mW
Operating Temperature Range ..........................-40°C to +85°C
Junction Temperature.....................................................+150°C
Storage Temperature.......................................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
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.
Required Field 
