MAX8934D 查看數據表（PDF） - Maxim Integrated

零件编号

产品描述 (功能)

生产厂家

MAX8934D

Dual-Input Linear Chargers, Smart Power Selector with Advanced Battery Temperature Monitoring

Maxim Integrated 

Dual-Input Linear Chargers, Smart Power Selector

with Advanced Battery Temperature Monitoring

Table 1. External Components List for Figures 2 and 3

COMPONENT

(Figures 2 and 3)

FUNCTION

PART NUMBER

CDC

DC filter capacitor

10FF ±10%, 16V X5R ceramic capacitor (0805)

Taiyo Yuden EMK212BJ106KG

CVL

VL filter capacitor

0.1FF ±10%, 10V X5R ceramic capacitor (0402)

Taiyo Yuden LMK105BJ104KV

CSYS

SYS output bypass capacitors

10FF ±10%, 6.3V X5R ceramic capacitor (0805)

Taiyo Yuden JMK212BJ106KD

CBATT

Battery bypass capacitor

4.7FF ±10%, 6.3V X5R ceramic capacitor (0805)

Taiyo Yuden JMK212BJ475KD

CCT

Charger timing capacitor

0.068FF ±10%, 16V X5R ceramic capacitor (0402)

Taiyo Yuden EMK105BJ683KV

CLDO

RPU (x5)

THM

RTHMSW

RPSET

RISET

LDO output capacitor

Logic-output pullup resistors

Negative TC thermistor

THM pullup resistor

DC input current-limit programming resistor

Fast-charge current programming resistor

1FF ±10%, 6.3V X5R ceramic capacitor (0402)

Taiyo Yuden JMK105BJ105KV

1MI ±5% resistor

Vishay NTC Thermistor P/N NTHS0603N01N1003FF

100kI

1.5kI ±1% for 2A limit

3kI ±1% for 1A charging

Detailed Description

The MAX8934_ is a dual-input linear charger with

Smart Power Selector that safely charges a single Li+/

Li-Poly cell in accordance with JEITA specifications.

The MAX8934_ integrates power MOSFETs and control

circuitry to manage power flow in portable devices. See

Figure 1. The charger has two power inputs, DC and

USB. These can be separately connected to an AC

adapter output and a USB port, or the DC input could be

a single power input that connects to either an adapter

or USB. Logic inputs, PEN1 and PEN2, select the cor-

rect current limits for two-input or single-input operation.

Figure 2 is the typical application circuit using separate

DC and USB connectors. Figure 3 is the typical applica-

tion circuit using a 5-pin USB connector or another DC/

USB common connector.

In addition to charging the battery, the MAX8934_ also

supplies power to the system through the SYS output.

The charging current is also provided from SYS so that

the set input current limit controls the total SYS current,

where total SYS current is the sum of the system load

current and the battery-charging current. SYS is pow-

ered from either the DC input pin or the USB sources

input pin. If both the DC and USB sources are con-

nected, DC takes precedence.

In some instances, there may not be enough adapter

current or USB current to supply peak system loads. The

MAX8934_ Smart Power Selector circuitry offers flexible

power distribution from an AC adapter or USB source

to the battery and system load. The battery is charged

with any available power not used by the system load.

If a system load peak exceeds the input current limit,

supplemental current is taken from the battery. Thermal

limiting prevents overheating by reducing power drawn

from the input source.

The MAX8934_ features an overvoltage limiter at SYS. If

the DC or USB input voltage exceeds the SYS regulation

voltage, VSYS does not follow VDC or VUSB, but remains

at its regulation voltage. The MAX8934_ has numerous

other charging and power-management features that are

detailed in the following sections.

A 3.3V ultra-low quiescent current, always-on LDO pro-

vides up to 30mA for indicator LEDs and for backup

power to the system. This LDO powers the thermistor

monitor circuitry and provides bias to the external pullup

resistor for the thermistor.

*JEITA (Japan Electronics and Information Technology Industries Association) Standard, A Guide to the Safe Use of Secondary

Lithium Ion Batteries on Notebook–Type Personal Computers, April 20, 2007.

______________________________________________________________________________________   19

Share Link: