Diodes APM8600 User Manual

APM8600

SINGLE CELL LINEAR LITHIUM BATTERY CHARGER

WITH 28V OVP AND PROGRAMMABLE CHARGE TIMER

Description

The APM8600 is a linear Li-Ion charger for portable equipment that is optimized for small form-factor applications.

The charge algorithm in the APM8600 covers all the charge requirements for a single Li-Ion battery cell. Included is precharging for deeply discharged cells, constant current / constant voltage fast charging and a top-off feature to bring the cell safely to a full-charge level.

The battery is constantly monitored for overvoltage, charge time and cell temperature to ensure safe charging. A fault is triggered once the charge time exceeds a value that is programmable using a single capacitor and the temper ature measurement is achieved through a thermistor positioned close to the battery cell.

The APM8600 is packaged in U-DFN3030-14 package with a thermal pad.

Applications

NEW PRODUCT

• Handheld Consumer Devices

• Cell Phones, PDAs, MP3 Players

• Handheld Test Equipment

• Digital Still Cameras

• Multimedia players

Pin Assignments

Figure 1 Pin Out

Features

• Linear Lithium Ion / Lithium Polymer charging IC

• Supply input safe up to 28V

• Fast charging with maximum current of 1A

• Resistor-programmable charging current

• Resistor programmable end-of-charge

• Capacitor programmable charge timer

• Three charge indicator pins for a status display

• Thermal protection

• DFN3030-14: Available in “Green” Molding Compound (No Br, Sb)

• Lead Free Finish/ RoHS Compliant (Note 1)

Note: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS

exemptions applied. Please visit our website at

http://www.diodes.com/products/lead_free.html

.

Typical Application Circuit

APM8600

Document number: DS35140 Rev. 1 - 2

Figure 2. Typical Application Circuit

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Pin Descriptions

APM8600

SINGLE CELL LINEAR LITHIUM BATTERY CHARGER

WITH 28V OVP AND PROGRAMMABLE CHARGE TIMER

NEW PRODUCT

Name Pin # Description

BAT 1, 7

SETI 2

THM 3 Thermistor Input

GND 4 Ground Ground connection.

CT 5 Charge Timing

EN

10

POK

11

CHG

DC 12, 13 DC Input

FLT

EP Exposed Pad

NC 7,9 Not Connected Floating pins

DNC 6 Do Not Connect Must not connect

14

Connection to the

Charge Current

8

Charge Status

Battery

programming

Enable

(active-low)

Power OK

(active-low)

Fault Flag

(active-low)

The battery is charged via this pin and the BAT voltage is constantly monitored. Connect a bypass capacitor between BAT and GND (2.2µF).

The maximum charge current is programmed using a resistor from SETI to GND. This also determines the prequal current charging level and top-off threshold.

To monitor the battery temperature, connect a 10kΩ NTC thermistor. Place this thermistor as close as possible to the battery. Connect THM to GND if temperature measurement is not required.

Connecting a capacitor from CT to GND will set the time-outs for prequal, top-off and fast-charge. Connecting CT direct to GND disables these timers.

The charger is enabled when this input is low. To start the charger connect GND. Drive this input high to disable the charger.

When a valid input source is connected, this open-drain output is pulled low. Open-drain output that indicates the charging status. It is active only in the fast-

charge state and goes high-impedance when the charger is either disabled or in prequal or top-off mode.

DC supply input. The recommended input voltage is between 4.32V and 7V. This input is capable of withstanding up to 28V. Connect both DC pins together on the PCB. It is recommended to connect a bypass capacitor (1µF) from DC to GND.

If the prequal or fast-charge timers expire and the charging threshold voltage is not reached, power or raise

For optimal thermal performance connect to copper on PCB (electrically this can be GND).

(open-drain output) will go low. Remove the fault by cycling

FLT

.

EN

to

EN

APM8600

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Functional Block Diagram

APM8600

SINGLE CELL LINEAR LITHIUM BATTERY CHARGER

WITH 28V OVP AND PROGRAMMABLE CHARGE TIMER

NEW PRODUCT

DC

SETI

EN CT

3.0V

4.2V

CHARGE

CONDITION

COMPARATORS

CHARGER REGULATOR

OVLO UVLO

V

DROP

PREQUAL

CHARGE

CONTROL

TIMER

THERMAL CURRENT

FOLDBACK

PROTECTION

1.5V

REFERENCE

BAT

THM

FLT

POR

APM8600

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GND

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CHG

December 2010

APM8600

SINGLE CELL LINEAR LITHIUM BATTERY CHARGER

WITH 28V OVP AND PROGRAMMABLE CHARGE TIMER

Absolute Maximum Ratings

Symbol Parameter Rating Unit

DC to GND -0.3 to 28V V

ESD Susceptibility (Note 2)

HBM Human Body Model 2 kV

MM Machine Model 200 V

Note: 2. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be

taken when handling and transporting this device.

BAT, CT, SETI, THM, to GND -0.3 to 6V

FLT

,

CHG, POK

Thermal Resistance (Note 3)

Symbol Parameter Rating Unit

θ

Junction to Ambient 40 °C/W

JA

Note: 3. Test condition for DFN3030-10: Device mounted on FR-4 2-layer board, 2oz copper, with minimum recommended pad on top layer and 6 vias to bottom layer 1.0”x1.5” ground plane.

NEW PRODUCT

, EN

V

Recommended Operating Conditions (Note 4)

Symbol Parameter Rating Unit

Ambient Temperature Range -40 to +85 °C

I

Typical Charge Current 0.1 to 1.0 A

CHARGE

Note: 4. The device function is not guaranteed outside of the recommended operating conditions.

Input Supply Voltage

4.15 to 7.00

V

APM8600

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Electrical Characteristics

APM8600 is tested at VDC = 5V, V otherwise noted.

Symbol Parameter Test Conditions Min Typ. Max Unit

NEW PRODUCT

V

DC

V

DC

UVLO

OVLO Input Overvoltage Lock Out

IDC Input Supply Current I

I

SHTDWN

R

DS_ON

V

DROPOUT

V

BAT_REG

BAT

RSTTH

I

DC_CHG

SS Soft-Start Time Ramp time to fast-charge 1.2 ms

V

PREQ_TH

I

LEAK

R

SETI

Note: 5. Guaranteed by testing of undervoltage- and overvoltage-threshold. To completely charge a battery cell, the input voltage must be greater than 4.32V.

Input Voltage Range 0 28 V Input Operating Range (Note 5) 4.15 7.00 V Input Undervoltage Lock Out

(Note 5)

Shutdown Current

Input to BAT On-Resistance Input = 3.7V, V

Input to BAT dropout Voltage

Battery Voltage Regulation I

Battery Fast-Charge Restart Threshold

DC Charge Current V

USB

BAT Prequel Threshold

BAT Leakage Current VDC = V

Resista nce Ra nge for SETI Guaranteed by charging current 1.5 5.0 kΩ

= 0V

WITH 28V OVP AND PROGRAMMABLE CHARGE TIMER

= 4V, VEN = 0V, R

BAT

APM8600

SINGLE CELL LINEAR LITHIUM BATTERY CHARGER

= 2kΩ, CCT = 68nF, at an ambient temperature of +25°C unless

SETI

Input rising, 500mV hysteresis

BAT

= 3.2V

(typ.) V Input rising, 200mV hysteresis

(typ.)

= 0mA, R

BAT

= High, TA = 25ºC

EN

= 10kΩ 750 1200 µA

THM

= 3.6V 0.5 0.8 Ω

BAT

Input falling, 200mV hysteresis (typ.)

= 0mA, TA = 25ºC 4.179 4.2 4.221 V

BAT

From BAT regulation voltage -230 -175 -110 mV R

= 1.5kΩ 950 1000 1140

SETI

R

= 2.0kΩ 727 750 870

SETI

R

= 5.0kΩ 280 300 353

SETI

Prequal, R

V

rising, 180mV hysteresis

BAT

= 2kΩ, V

SETI

= 2.5V 60 75 95

BAT

(typ.)

USB

= 0V, V

= 4.2V 0.001 5 µA

BAT

3.85 4.0 4.15 V

7.2 7.5 7.8 V

275 435 µA

5 55 150 mV

mA

2.9 3.0 3.1 V

APM8600

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