Maxim > Products > Power and Battery Management > MAX1920, MAX1921

MAX1920, MAX1921

Low-Voltage, 400mA Step-Down DC-DC Converters in SOT23

Overview

Technical Documents

Ordering Info

Status

Active: In Production.

Description

The MAX1920/MAX1921 step-down converters deliver over 400mA to outputs as low as 1.25V. These converters use a unique proprietary current-limited control scheme that achieves over 90% efficiency. These devices maintain extremely low quiescent supply current (50µA), and their high 1.2MHz (max) operating frequency permits small, low-cost external components. This combination makes the MAX1920/MAX1921 excellent high-efficiency alternatives to linear regulators in space-constrained applications.

Internal synchronous rectification greatly improves efficiency and eliminates the external Schottky diode required in conventional step-down converters. Both devices also include internal digital soft-start to limit input current upon startup and reduce input capacitor requirements.

The MAX1920 provides an adjustable output voltage (1.25V to 4V). The MAX1921 provides factory-preset output voltages (see the Selector Guide). Both are available in space-saving 6-pin SOT23 packages. The MAX1920 is also available in a 6-pin TDFN package.

Data Sheet

Download	Rev 3	(PDF, 804kB)
E-Mail

An evaluation kit is available: MAX1921EVKIT

Key Features

400mA Guaranteed Output Current
Internal Synchronous Rectifier for >90% Efficiency
Tiny 6-Pin SOT23 Package
Up to 1.2MHz Switching Frequency for Small External Components
50µA Quiescent Supply Current
0.1µA Logic-Controlled Shutdown
2V to 5.5V Input Range
Fixed 1.5V, 1.8V, 2.5V, 3V, and 3.3V Output Voltages (MAX1921)
Adjustable Output Voltage (MAX1920)
±1.5% Initial Accuracy
Soft-Start Limits Startup Current

Applications/Uses

Battery-Powered Applications
CDMA Power Amplifier Supply
Next-Generation Wireless handsets
PDAs, Palmtops, and Handy Terminals

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

MAX1920

5.5

1.25

0.4

Resistor

1200

SOT/6

TDFN-EP/6

$1.35 @1k

MAX1921

1.5

3.3

1.5

1.8

2.5

3.3

Preset

Resistor

SOT/6

$1.35 @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

Application Note 3741

Analog ICs for Low Voltage Systems

Reliability Reports

Reliability Report:	MAX1920.pdf MAX1921.pdf
Show FIT data 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
MAX1920ETT+			Active	TDFN-EP;6 pin;9.6 mm² Outline Drawing:21-0137 (PDF) Land Pattern: 90-0058 (PDF) Use pkgcode/variation: T633+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1920ETT+T			Active	TDFN-EP;6 pin;9.6 mm² Outline Drawing:21-0137 (PDF) Land Pattern: 90-0058 (PDF) Use pkgcode/variation: T633+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1920EUT+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1920EUT+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1920EUT-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT15+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT15+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT15-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT18+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT18+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-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
MAX1921EUT18-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT25+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT25+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT25-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT30			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT30+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT30+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT30-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX1921EUT33+			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX1921EUT33+T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN+1*	-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
MAX1921EUT33-T			Active	SOT;6 pin;9 mm² Outline Drawing:21-0058 (PDF) Land Pattern: 90-0175 (PDF) Use pkgcode/variation: U6SN-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis

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.

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Evaluation Kits

MAX1921EVKIT

Evaluation Kit for the MAX1920, MAX1921

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