Linear Technology LTC3554EPD User manual

DEMO CIRCUIT 1468

QUICK START GUID

LTC3554EPD

Micropower USB Power Manage

with Two Step-Down Regulators

DESCRIPTION

Demonstration Circuit DC1468A is a Micropower USB Power Manager with Two Step-Down Regulators featuring

the LTC®3554.

PERFORMANCE SUMMARY

Specifications are at T

= 25°C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VBUS

Bus Input Voltage Range 4.35 6 V

V(BAT)

Battery Float Voltage Constant Voltage Mode 4.15 4.23 V

I(BAT)

Battery Charge Current Constant Current Mode, R

PROG

= 1.87k

420 500 mA

VOUT1

Output Voltage 1 I(VOUT1) ≤ 200mA 3.25 3.35 V

VOUT2

Output Voltage 2 I(VOUT2) ≤ 200mA 1.15 1.25 V

QUICK START PROCEDURE

Refer to Figure 1 for the proper measurement

equipment setup and jumper settings and follow the

procedure below.

NOTE.

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 voltage ripple by touching the

probe tip directly across the VBUS or VOUT(x) and GND terminals.

See Figure 2 for proper scope probe technique.

1. Set PS1 = 0V, PS2 = 3.6V. Press “ON” button

for > 0.5s. Observe I(BAT) (AM2), VOUT1 (VM5)

and VOUT2 (VM6). The regulator ENable lines

are low. Pressing the “ON” button turns on the

regulators for 5s, via the pushbutton controller.

The regulator ENables are bootstrapped to the

outputs of the regulators, so regulators stay on

indefinitely. The STBY jumper is on, so the

LTC3554 draws only ~10μA from the battery.

2. Set STBY (JP4) to “OFF”, PS1 to 5V. Observe

I(VBUS) (AM1), I(BAT) (AM2) and VPROG

(VM2). The STBY jumper is off, and the battery

charger is trying to charge the battery at 500mA,

but the input current limit is keeping the charge

current at 100mA.

3. Set HPWR (JP2) to “500mA”. Observe I(VBUS)

(AM1), I(BAT) (AM2) and VPROG (VM2). The

input current limit is now 500mA, so the battery

charger is charging at 450mA, and the buck

regulators are unloaded.

4. Set LD2 to 200mA, LD3 to 200mA. Observe

VOUT1(VM5), VOUT2 (VM6) and I(BAT) (AM2).

The buck regulators are each loaded at 200mA.

These loads are reflected back to the VBUS input

by the ratio of their output voltage to the VOUT

Voltage. The buck regulators are higher priority

Downloaded from Arrow.com.

LTC3554EPD

than the battery charger, so the charger is only

charging at the input current limit of 500mA mi-

nus the reflected buck regulator loads, ~200mA.

5. Set LD2 to 0A, LD3 to 0A. Press “OFF” button.

Observe VOUT1 (VM5) and VOUT2 (VM6). The

“OFF” button momentarily brings the ENable

lines low, shutting regulators off. The battery

charge current should now return to 450mA.

6. Reset the Jumpers to their default position.

Downloaded from Arrow.com.Downloaded from Arrow.com.

LTC3554EPD

Figure 1. Proper Measurement Equipment Setup for DC1468A

VIN

GND

Figure 2. Measuring Input or Output Ripple

PS1 +

4.35V - 5.5V supply

1A -

VM1

+ PS2

0V - 5V supply

1 1

3.6

Ω

VM4

+ -

AM2

VM3

+ -

AM1

Note: All connections from equipment should be Kelvin connected directly to the board

pins which they are connected on this diagram and any input or output leads should be

twisted pair.

VM5

+ -

+ LD2

0V - 5V

- 2

AM3

VM6

+ -

+ LD3

0V - 5V

- 2

AM4

VM2

Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

LTC3554EPD

Figure 3. Circuit Schematic

Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

LTC3554EPD

Figure 4. Bill of Materials

Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.

This manual suits for next models

Other Linear Technology Motherboard manuals

Linear Technology

Linear Technology DC1041A-B User manual

Linear Technology

Linear Technology DC1554 Quick setup guide

Linear Technology

Linear Technology DC2347A Quick setup guide

Linear Technology

Linear Technology DC1317A User manual

Linear Technology

Linear Technology DC416 Quick setup guide

Linear Technology

Linear Technology DC2073A Series Quick setup guide

Linear Technology

Linear Technology 968A-B User manual

Linear Technology

Linear Technology DC1925A Series Quick setup guide

Linear Technology

Linear Technology DC1817B Quick setup guide

Linear Technology

Linear Technology DC1762A Quick setup guide

Linear Technology

Linear Technology DC1682B Quick setup guide

Linear Technology

Linear Technology DC1729A Quick setup guide

Linear Technology

Linear Technology DC2118A Quick setup guide

Linear Technology

Linear Technology DC2268A-E Quick setup guide

Linear Technology

Linear Technology DC2183A Quick setup guide

Linear Technology

Linear Technology DC1784A Quick setup guide

Linear Technology

Linear Technology LTC2270 Quick setup guide

Linear Technology

Linear Technology DC2143A-B User manual

Linear Technology

Linear Technology DC1400A Quick setup guide

Linear Technology

Linear Technology DC861A-A User manual

Linear Technology

Linear Technology DC1959A Quick setup guide

Linear Technology

Linear Technology DC1496B Quick setup guide

Linear Technology

Linear Technology DC1667A Quick setup guide

Linear Technology

Linear Technology DC1537A Quick setup guide

Popular Motherboard manuals by other brands

DFI

DFI SD170 user manual

ASROCK

ASROCK ROMED8-2T user manual

Asus

Asus P2L97A user manual

Winmate

Winmate IC70 user manual

Asus

Asus MES-B user manual

Grantech

Grantech SYS8F377VGGA-3OMN user manual

Telit Wireless Solutions

Telit Wireless Solutions SL869-3DR user guide

Gigabyte

Gigabyte GA-9IVDT user manual

Texas Instruments

Texas Instruments ADS8372EVM user guide

Commell

Commell MS-C73 user manual

IBT Technologies

IBT Technologies MB860 user manual

Nvidia

Nvidia TEGRA DG-04927-001_V01 user guide

Biostar

Biostar M7VIT Bravo Description

Intel

Intel D33217CK specification

Asus

Asus F1A55-M LX PLUS R2.0 user manual

EPC

EPC EPC9147C quick start guide

Asus

Asus EX-B760M-V5 D4 quick start guide

EPOX

EPOX MU-8KHA0010 user manual