Maxim > Products > Power and Battery Management > MAX1649, MAX1651

MAX1649, MAX1651

5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC Controller

High-Efficiency Step-Down Controller Operates with 4 to 8 Cells

Overview

Technical Documents

Ordering Info

Status

Active: In Production.

Description

The MAX1649/MAX1651 BiCMOS, step-down, DC-DC switching controllers provide high efficiency over loads ranging from 1mA to more than 2.5A. A unique, current-limited pulse-frequency-modulated (PFM) control scheme gives these devices the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using only 100µA of supply current (vs. 2mA to 10mA for PWM converters). Dropout performance down to 300mV is provided by a high switch duty cycle (96.5%) and a low current-sense threshold (110mV).

A high switching frequency (up to 300kHz) allows these devices to use miniature external components.

The MAX1649/MAX1651 have dropout voltages less than 0.3V at 500mA and accept input voltages up to 16V. Output voltages are preset at 5V (MAX1649), or 3.3V (MAX1651). They can also be adjusted to any voltage from 1.5V to the input voltage by using two resistors.

These step-down controllers drive external P-channel MOSFETs at loads greater than 12.5W. If less power is required, use the MAX639/MAX640/MAX653 step-down converters with on-chip FETs, which allow up to a 225mA load current.

Data Sheet

Download	Rev 3	(PDF, 228kB)
E-Mail

An evaluation kit is available: MAX1649EVKIT

Key Features

More than 90% Efficiency (10mA to 1.5A Loads)
More than 12.5W Output Power
Less than 0.3V Dropout Voltage at 500mA
100µA Max Quiescent Supply Current
5µA Max Shutdown Supply Current
16V Max Input Voltage
5V (MAX1649), 3.3V (MAX1651), or Adjustable Output Voltage
Current-Limited Control Scheme
Up to 300kHz Switching Frequency
Up to 96.5% Duty Cycle

Applications/Uses

5V to 3.3V Green PC Applications
Battery-Powered Applications
High-Efficiency Step-Down Regulation
PDAs

Key Specifications:

Step-Down Switching Regulators

Part Number

V_IN
(V)

V_OUT
(V)

Preset V_OUT
(V)

Max. I_OUT
(A)

Output Adjust. Method

DC-DC Outputs

Oper. Freq.
(kHz)

Package/Pins

Smallest Available Pckg.
(mm²)

Budgetary Price

min

max

min

max

≥

≤

max w/pins

See Notes

MAX1649

1.5

2.5

Preset

Resistor

300

PDIP(N)/8

SOIC(N)/8

79.7

$2.13 @1k

MAX1651

3.3

PDIP(N)/8

SOIC(N)/8

30.9

$2.13 @1k

See All Step-Down Switching Regulators (284)

Pricing 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.

Diagram

Typical Operating Circuit

Application Notes

Tutorial 671		Energy Management for Small Portable Systems
Application Note 4326		Reduce Standby Power Drains with Ultra-Low-Current, Pulse-Frequency-Modulated (PFM) DC-DC Converters

Reliability Reports

Show FIT data for:
Request Reliability Report for:

Software/Models

none

Ordering Information

Filters:

Part Number:

Package:

Temperature:

Tape and Reel

Sample

Part Number	Free Sample	Buy	Status	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX1649CPA			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8-2*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
MAX1649CPA+			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8+2*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1649CSA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
MAX1649CSA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1649CSA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1649CSA-T			Active	N.SO;8 pin Land Pattern: Not Available	0°C to +70°C	See data sheet
MAX1649EPA			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1649EPA+			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1649ESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1649ESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
Part Number	Free Sample	Buy	Status	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX1649ESA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1649ESA-T			Active	N.SO;8 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX1649MJA			Active	Land Pattern: Not Available		See data sheet
MAX1651CPA			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8-2*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
MAX1651CSA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
MAX1651CSA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1651CSA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1651CSA-T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
MAX1651EPA			Active	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1651ESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
Part Number	Free Sample	Buy	Status	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX1651ESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1651ESA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+4*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1651ESA-T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1651MJA			Active	Land Pattern: Not Available		See data sheet

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Notes and Comments

Drives external P-channel FET, low I_Q

Similar Products by Function

MAX639, MAX640, MAX653	5V/3.3V/3V Adjustable, High-Efficiency, Low-I_Q, Step-Down DC-DC Converters
MAX1626, MAX1627	5V/3.3V or Adjustable, 100% Duty Cycle, High-Efficiency, Step-Down DC-DC Controllers
See All Step-Down Switching Regulators (310 Products)

Evaluation Kits

MAX1649EVKIT

Evaluation Kit for the MAX649, MAX651, MAX652 and MAX1649, MAX1651

Products with Similar Part Numbers