Linear Technology LTC3542 Manuel utilisateur

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 993

500MA, 2.25 MHZ SYNCHRONOUS STEP-DOWN REGULATOR

LTC3542

DESCRIPTION

Demonstration circuit 993A is a step-down converter,

using the LTC3542 monolithic synchronous buck regula-

tor. The DC993A has an input voltage range of 2.5V to

5.5V, and is capable of delivering up to 500 mA of output

current in a small 2x2 mm DFN package. The output

voltage of the DC993A can be set as low as 0.6V, the

reference voltage of the LTC3542. At low load currents,

the DC993A can operate in either noise sensitive applica-

tions, due to the capability of the LTC3542 to operate in

pulse-skipping mode, or in high efficiency applications,

because the LTC3542 can also operate in Burst Mode.

Of course, in continuous mode, or large load current

applications, the DC993A is a high efficiency circuit -

over 90% in some cases. The DC993A consumes only

27 uA during sleep mode operation, and during shut-

down, it consumes at less than 1 uA. Because of the

high switching frequency of the LTC3542 – nominal 2.25

MHz - the DC993A uses low profile surface mount com-

ponents. These features, plus the LTC3542 coming in a

either a tiny 2x2 mm 6-Lead DFN package or a small 6-

Lead SOT package, make the DC993A an ideal circuit for

use in battery-powered, hand-held applications.

Gerber

files for this circuit are available. Call the LTC Fac-

tory.

Table 1. Performance Summary (TA= 25°C)

PARAMETER CONDITIONS VALUE

Minimum Input Voltage 2.5V

Maximum Input Voltage 5.5V

GND = Shutdown

Run/Shutdown VIN = Run

1.2V ±4% (1.152V – 1.248V)

1.5V ±4% (1.44V - 1.56V)

Output Voltage VOUT

VIN = 2.5V to 5.5V, IOUT = 0A to 500 mA

1.8V ±4% (1.728V – 1.872V)

Typical Output Ripple VOUT VIN = 5V, IOUT = 500 mA (20 MHz BW) < 20mVP–P

Line ±1%

Output Regulation

Load ±1%

Nominal Switching Frequency 2.25 MHz

Burst Mode - VIN = 3.6V, VOUT = 1.8V ~60 mA ± 10 mA

Operation Modes

Pulse-Skip - VIN = 3.6V, VOUT = 1.8V ~60 mA ± 10 mA

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 993

500MA, 2.25 MHZ SYNCHRONOUS STEP-DOWN REGULATOR

QUICK START PROCEDURE

emonstration Circuit 993 is easy to set up to evalu-

ate the performance of the LTC3542. For proper

measurement equipment configuration, set up the

circuit according to the diagram in Figure 1. Before

proceeding to test, insert shunts into the OFF position

of header JP3, which connects the RUN pin to ground

(GND), and thus, shuts down the circuit, and the 1.2V

output voltage header – JP4.

When measuring the input or output voltage ripple,

care must be taken to avoid a long ground lead on the

oscilloscope probe. Measure the input or output volt-

age ripple by touching the probe tip directly across

the Vin or Vout and GND terminals. See Figure 2 for

proper scope probe measurement technique.

With the DC993 set up according to the proper meas-

urement and equipment in Figure 1, apply 3.3V at Vin

(Do not hot-plug Vin or increase Vin over the rated

maximum supply voltage of 5.5V, or the part may be

damaged.). Measure Vout; it should read 0V. If de-

sired, one can measure the shutdown supply current

at this point. The supply current will be approxi-

mately 1 uA, or less, in shutdown.

Turn on the circuit by inserting the shunt in header

JP3 into the ON position. The output voltage should

be regulating. Measure Vout - it should measure

1.2V +/- 2% (1.176V to 1.224V).

Vary the input voltage from 2.5V to 5.5V and adjust

the load current from 0 to 500 mA. Vout should read

between 1.2V +/- 4% (1.152V to 1.248V).

Measure the output ripple voltage at any output cur-

rent level; it usually will measure less than 30 mVAC.

Observe the voltage waveform at the switch node.

Verify the switching frequency is between 1.8 MHz

and 2.7 MHz (T = 0.555 us and 0.37 us), and that the

switch node waveform is rectangular in shape.

Insert header JP3 shunt into the OFF position and move

the 1.2V Vout shunt into any of the two remaining output

voltage option headers: 1.5V or 1.8V. Just as in the

1.2Vout test, the output voltage should read Vout +/- 2%

tolerance under static line and load conditions, and +/-

1% tolerance under dynamic line and load conditions

(+/- 2% total).

When finished, turn off the circuit by inserting the

shunt in header JP3 into the OFF position (connecting

the RUN pin to ground).

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 993

500MA, 2.25 MHZ SYNCHRONOUS STEP-DOWN REGULATOR

Demonstration circuit 993 is a step-down converter based on the LTC3542 monolithic synchronous buck regulator.

The DC993 is easy to set up and evaluate the performance of the LTC3542. Refer to Figure 1 for proper equipment

set-up

Figure 1. Proper Equipment Measurement Set-Up

Figure 2. Measuring Input or Output Ripple

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 993

500MA, 2.25 MHZ SYNCHRONOUS STEP-DOWN REGULATOR

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Analog Devices Inc.:

DC993A

Ce manuel convient aux modèles suivants

Table des matières

Autres manuels Linear Technology Contrôleurs

Linear Technology

Linear Technology LT3507A Guide de configuration rapide

Linear Technology

Linear Technology DC2007A-B Guide de configuration rapide

Linear Technology

Linear Technology LT1761 Manuel utilisateur

Linear Technology

Linear Technology LTM4613 Guide de configuration rapide

Linear Technology

Linear Technology LT8570 Guide de configuration rapide

Linear Technology

Linear Technology DC1814A Guide de configuration rapide

Linear Technology

Linear Technology Analog Devices LTM4622A Manuel utilisateur

Linear Technology

Linear Technology LT3755 Manuel utilisateur

Linear Technology

Linear Technology LT8390A Guide de configuration rapide

Linear Technology

Linear Technology LTM4645 Guide de configuration rapide

Linear Technology

Linear Technology LT1425 Manuel utilisateur

Linear Technology

Linear Technology DC1989A-A Guide de configuration rapide

Linear Technology

Linear Technology LT8610A Guide de configuration rapide

Linear Technology

Linear Technology DC1613A Guide de configuration rapide

Linear Technology

Linear Technology LTC2920-1CS5 Manuel utilisateur

Linear Technology

Linear Technology DC1855A Guide de configuration rapide

Linear Technology

Linear Technology 1814A Guide de configuration rapide

Linear Technology

Linear Technology DC1831A Manuel utilisateur

Linear Technology

Linear Technology LTM8027 Guide de configuration rapide

Linear Technology

Linear Technology LTM8003 Guide de configuration rapide

Linear Technology

Linear Technology LTM4630EY-1 Guide de configuration rapide

Linear Technology

Linear Technology LTC7138 Guide de configuration rapide

Linear Technology

Linear Technology LTC3212 Manuel utilisateur

Linear Technology

Linear Technology LTM4677EY Guide de configuration rapide

Manuels Contrôleurs populaires d'autres marques

Digiplex

Digiplex DGP-848 Mode d'emploi

YASKAWA

YASKAWA SGM series Manuel utilisateur

Sinope

Sinope Calypso RM3500ZB Manuel utilisateur

Isimet

Isimet DLA Series Style 2 Manuel d'installation

LSIS

LSIS sv-ip5a Manuel utilisateur

Rockwell Automation

Rockwell Automation 1769-L31 Manuel utilisateur

Airflow

Airflow Uno hab Manuel utilisateur

ABB

ABB ACS580-01 drives Manuel utilisateur

Panasonic

Panasonic GM1 Series Manuel utilisateur

Emerson

Emerson SW93 Manuel utilisateur

AutoAqua

AutoAqua Smart ATO micro SATO-120P Manuel utilisateur

Panasonic

Panasonic FP? Positioning Unit RTEX Manuel utilisateur

Samson

Samson Type 5824 Manuel de service

Alpha IP

Alpha IP MIOB 21001 Manuel utilisateur

Siemens

Siemens OpenAir GMA 1 Series Manuel utilisateur

Surecom

Surecom SR-629 Manuel utilisateur

Fishman

Fishman TriplePlay Manuel utilisateur

Regulus

Regulus SRS1 T Manuel utilisateur