MAXIM MAX1920, MAX1921 Technical data

General Description

The MAX1921 evaluation kit (EV kit) provides a fixed 1.8V
output voltage from a 2V to 5.5V input source and deliv­ers up to 400mA output current. The MAX1921 is a step­down switching regulator with an internal power switch
and synchronous rectifier in a tiny SOT23 package.

The MAX1921 EV kit is a fully assembled and tested
surface-mount circuit board. The MAX1921 EV kit can
also be used to evaluate other fixed-output voltage ver­sions of the MAX1921 or the MAX1920, which is a step­down switching regulator with an adjustable output volt­age. Additional pads on the board are provided for
external feedback resistors to set different output volt­ages, 1.25V to VIN.

Features

♦ 2V to 5.5V Input Voltage Range

♦ Output Voltage

1.8V Fixed Output Voltage (MAX1921EUT18-T)
Adjustable Output Voltage (MAX1920EUT-T)
Other Fixed-Output Voltages

(MAX1921EUT_ _-T)

♦ Output Current

Guaranteed 400mA at ≥2.5V Input Voltage

♦ IC Shutdown Current

0.1µA (typ)

♦ Surface-Mount Components

♦ Fully Assembled and Tested

Evaluates: MAX1920/MAX1921

MAX1921 Evaluation Kit

________________________________________________________________ Maxim Integrated Products 1

19-2361; Rev 0; 03/02

Component List

Ordering Information

Note: To evaluate other versions of the MAX1921 or the
MAX1920, request a free sample with the MAX1921EVKIT.
See Table 2.

Quick Start

The MAX1921 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below to verify
board operation. Do not turn on the power supply

until all connections are completed:

1) Verify that there is a shunt across pins 1 and 2 of

JU1 (SHDN).

2) Connect a voltmeter and load (if any) to the VOUT
pad. Connect the ground to the GND closest to
VOUT.

3) Connect a 2V to 5.5V power supply to the VIN pad.
Connect power supply ground to the GND pad
closest to VIN.

4) Turn on the power supply and verify that the output
voltage is 1.8V.

To evaluate other voltages, see the Evaluating Other
Output Voltages section.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

查询MAX1921EVKIT供应商

DESIGNATION QTY DESCRIPTION

C1 1

C2 1

C3 1

JU1 1 3-pin header

L1 1

R1 1 4.75kΩ ±1% resistor (0603)

R2 0 Not installed, resistor (0603)

U1 1

None 1 Shunt

None 1 MAX1921 PC board

None 1 MAX1921 EV kit data sheet

None 1 MAX1920/MAX1921 data sheet

2.2µF ±20%, 10V X5R
ceramic capacitor (0805)
Taiyo Yuden LMK212BJ225MG or
TDK C2012X5R1A225M

4.7µF ±20%, 6.3V X5R
ceramic capacitor (0805)
Taiyo Yuden JMK212BJ475MG or
TDK C2012X5R0J475K

5.6nF ±20%, 50V X7R
ceramic capacitor (0603)
Murata GRM39X7R562M050AD or
equivalent

4.7µH ±20% 1A inductor
Toko A914BYW-4R7M or
Sumida CDRH3D16-4R7

MAX1921EUT18-T
(6-pin SOT23), top mark ABCM

PART TEMP RANGE IC PACKAGE

MAX1921EVKIT 0

o

C to +70oC 6 SOT23-6

Evaluates: MAX1920/MAX1921

MAX1921 Evaluation Kit

2 _______________________________________________________________________________________

Component Suppliers

Table 1. JU1 Functions

Table 2. MAX1921 EV Kit Corresponding
Output Voltage

Detailed Description

Shutdown Mode

The MAX1921 EV kit features a shutdown mode that
reduces the MAX1921 quiescent current to 0.1µA, pre­serving battery life. The setting of jumper JU1 selects
the circuit operating modes. Table 1 shows the func­tions of JU1.

Evaluating Other Output Voltages

The MAX1921 EV kit can be used to evaluate the
MAX1921EUT15-T/25-T/30-T/33-Tand the MAX1920EUT-T.
Replace MAX1921EUT18-T with a MAX1921EUT15-T/25­T/30-T/33-T or MAX1920EUT-T. Table 2 lists the corre­sponding output voltages. To evaluate different output
voltages, select L1, C2, C3, R1, and R2 for optimum per­formance according to the Design Procedure section of
the MAX1920/MAX1921 data sheet.

Note: Please indicate that you are using the MAX1920/MAX1921 when contacting these component suppliers.

SUPPLIER PHONE FAX WEBSITE

Sumida 847-545-6700 847-545-6720 www.sumida.com

Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com

TDK 847-803-6100 847-390-4405 www.tdk.com

Toko 847-297-0070 847-699-1194 www.tokoam.com

SHUNT

LOCATION

1 and 2

2 and 3

Open

SHDN PIN MAX1921 OUTPUT

Connected to

VIN

Connected to

GND

Connected to

SHDN pad

MAX1921 enabled,

VOUT = 1.8V

MAX1921 disabled,

VOUT = 0V

External signal

enables or disables

the MAX1921 output

PART NUMBER

MAX1920EUT-T Adjustable

MAX1921EUT15-T 1.5

MAX1921EUT18-T 1.8

MAX1921EUT25-T 2.5

MAX1921EUT30-T 3.0

MAX1921EUT33-T 3.3

MAX1921 EV KIT OUTPUT

VOLTAGE (V)