MAX1777, MAX1977, MAX1999 High-Efficiency, Quad Output, Main Power-Supply Controllers for Notebook Computers

QuickView

Technical Documents

Ordering Info

More Information

All

Description

FULL DATA SHEET (PDF, 512kB)

Download

E-Mail

The MAX1777/MAX1977/MAX1999 dual step-down, switch-mode power-supply (SMPS) controllers generate logic-supply voltages in battery-powered systems. The MAX1777/MAX1977/MAX1999 include two pulse-width modulation (PWM) controllers, adjustable from 2V to 5.5V or fixed at 5V and 3.3V. These devices feature two linear regulators providing 5V and 3.3V always-on outputs. Each linear regulator provides up to 100mA output current with automatic linear regulator bootstrapping to the main SMPS outputs. The MAX1777/MAX1977/MAX1999 include on-board power-up sequencing, a power-good (PGOOD) output, digital soft-start, and internal soft-stop output discharge that prevents negative voltages on shutdown.

Maxim's proprietary Quick-PWM™ quick-response, constant on-time PWM control scheme operates without sense resistors and provides 100ns response to load transients while maintaining a relatively constant switching frequency. The unique ultrasonic pulse-skipping mode maintains the switching frequency above 25kHz, which eliminates noise in audio applications. Other features include pulse skipping, which maximizes efficiency in light-load applications, and fixed-frequency PWM mode, which reduces RF interference in sensitive applications.

The MAX1777 features a 200kHz/5V and 300kHz/3.3V SMPS for highest efficiency, while the MAX1977 features a 400kHz/5V and 500kHz/3.3V SMPS for “thin and light” applications. The MAX1999 provides a pin-selectable switching frequency, allowing either 200kHz/300kHz or 400kHz/500kHz operation of the 5V/3.3V SMPSs, respectively. The MAX1777/MAX1977/MAX1999 are available in 28-pin QSOP packages and operate over the extended temperature range (-40°C to +85°C). The MAX1777/ MAX1977/MAX1999 are available in lead-free packages.

Key Features

Applications/Uses

	No Current-Sense Resistor Needed (MAX1999)
	Accurate Current Sense with Current-Sense Resistor (MAX1777/MAX1977)
	1.5% Output Voltage Accuracy
	3.3V and 5V 100mA Bootstrapped Linear Regulators
	Internal Soft-Start and Soft-Stop Output Discharge
	Quick-PWM with 100ns Load Step Response
	3.3V and 5V Fixed or Adjustable Outputs (Dual Mode™)
	4.5V to 24V Input Voltage Range
	Ultrasonic Pulse-Skipping Mode (25kHz min)
	Power-Good (PGOOD) Signal
	Overvoltage Protection Enable/Disable

	3- and 4-Cell Li+ Battery-Powered Devices
	Notebook and Subnotebook Computers
	PDAs and Mobile Communication Devices

Key Specifications: Switch-Mode DC-DC Power Supplies

Part Number

Topology

V_IN (min) (V)

V_IN (max) (V)

Number of DC-DC Outputs

Preset V_OUT (V)

Digital/VID Programmed Output

Min. Adjustable V_OUT (V)

Max. Adjustable V_OUT (V)

I_OUT (A)

Fixed Freq/PWM Operation

Operating Freq. (kHz)

Internal Power Switch(es)

Synchronous Rectifier

Package

Smallest Available Package (max w/pins) (mm²)

Price^**

MAX1777

Step-Down

3.3

5.5

Yes

200
300

Yes

QSOP/28

$4.80 @ 1k

MAX1977

400
500

$4.80 @ 1k

MAX1999

200
300
400
500

$4.80 @ 1k

See All Switch-Mode DC-DC Power Supplies (421)

Notes:
^**This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.