MICROCHIP MCP73811, MCP73812 Technical data

MCP73811/2

V

DD

V

BAT

5

5-Pin SOT-23

1

3

4

2

CE

PROG

V

SS

Simple, Miniature Single-Cell, Fully Integrated

Li-Ion / Li-Polymer Charge Management Controllers

Features

• Complete Linear Charge Management Controller

- Integrated Pass Transistor

- Integrated Current Sense

- Integrated Reverse Discharge Protection

• Constant Current / Constant Voltage Operation with Thermal Regulation

• High Accuracy Preset Voltage Regulation: +

• Voltage Regulation: 4.20V

• Selectable Charge Current:

- MCP73811: 85 mA / 450 mA

• Programmable Charge Current:

- MCP73812: 50 mA - 500 mA

• Minimum External Components Required:

- MCP73811: 2 Ceramic Capacitors

- MCP73812: 2 Ceramic Capacitors and

1 Resistor

• No Preconditioning

• External End-of-Charge Control

• Automatic Power-Down when Input Power Removed

• Active High Charge Enable

• Temperature Range:

- -40°C to +85°C

• Packaging:

- 5-Lead SOT-23

1%

Applications

Description

The MCP73811/2 devices are linear charge management controllers that are designed for use in space limited and cost sensitive applications. The MCP73811/2 provide specific charge algorithms for single cell Li-Ion or Li-Polymer battery to achieve optimal capacity in the shortest charging time possible. Along with its small physical size, the low number of external components required make the MCP73811/2 ideally suited for portable applications. For applications charging from a USB port, the MCP73811 adheres to all the specifications governing the USB power bus.

The MCP73811/2 employ a constant current/constant voltage charge algorithm. The constant voltage regulation is fixed at 4.20V, with a tight regulation tolerance of 1%. For the MCP73811, the constant current value is selected as 85 mA (low power USB port) or 450 mA (high power USB port) with a digital input signal on the PROG input. For the MCP73812, the constant current value is set with one external resistor. The MCP73811/2 limit the charge current based on die temperature during high power or high ambient conditions. This thermal regulation optimizes the charge cycle time while maintaining device reliability.

The MCP73811/2 are fully specified over the ambient temperature range of -40°C to +85°C. The MCP73811/2 are available in a 5-Lead, SOT-23 package.

Package Types

• Low-Cost Lithium-Ion/Lithium-Polymer Battery Chargers

• Rechargeable Toys

• Electronic Cigarettes

• Bluetooth Headsets

• USB Chargers

MCP73811/2

CE

V

DD

V

SS

PROG

V

BAT

+

-

Single Li-Ion Cell

4

MCP73812

5

3

1

500 mA Li-Ion Battery Charger

2

2kΩ

CE

V

DD

V

SS

PROG

V

BAT

+

-

Single Li-Ion Cell

4

MCP73811

5

3

1

1µF

450 mA Li-Ion Battery Charger

2

V

IN

1µF

V

IN

1µF

+

-

Reference Generator

V

REF

(1.21V)

V

BAT

V

DD

V

BAT

G=0.001

V

SS

Direction

Control

+

-

Direction Control

6µA

+

-

CA

157.3 kΩ

388.7 kΩ

+

-

VA

CE

Charge Enable

2.7 kΩ

PROG

111 kΩ

528.6 kΩ

MCP73811MCP73812

12 kΩ

Typical Applications

Functional Block Diagram

MCP73811/2

1.0 ELECTRICAL

CHARACTERISTICS

† Notice: Stresses above those listed under “Maximum

Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those

Absolute Maximum Ratings†

V

................................................................................7.0V

DDN

All Inputs and Outputs w.r.t. V

Maximum Junction Temperature, T

Storage temperature .....................................-65°C to +150°C

ESD protection on all pins

Human Body Model (1.5 kW in Series with 100 pF) ......≥ 4kV

Machine Model (200pF, No Series Resistance)..............400V

............... -0.3 to (VDD+0.3)V

SS

............ Internally Limited

J

indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

DC CHARACTERISTICS

Electrical Specifications: Unless otherwise indicated, all limits apply for VDD= [V

T

= -40°C to +85°C. Typical values are at +25°C, V

A

DD

= [V

(typ.) + 1.0V]

REG

Parameters Sym Min Typ Max Units Conditions

Supply Input

Supply Voltage V

Supply Current I

DD

SS

3.75 — 6 V

— 1000 1500 µA Charging

— 50 100 µA Standby (CE = V

— 1.2 5 µA Shutdown

Voltage Regulation (Constant Voltage Mode)

Regulated Output Voltage V

Output Voltage Tolerance V

Line Regulation |(ΔV

Load Regulation |ΔV

REG

RTOL

BAT/VBAT

/ΔV

|

DD

BAT/VBAT

| — 0.09 0.30 % I

—4.20—VV

-1 — +1 % TA=-5°C to +55°C

)

— 0.09 0.30 %/V V

Supply Ripple Attenuation PSRR — 52 — dB I

—47—dBI

—22—dBI

Current Regulation (Fast Charge Constant-Current Mode)

Fast Charge Current I

REG

— 85 — mA MCP73811 - PROG = Low

Regulation — 450 — mA MCP73811 - PROG = High

— 50 — mA MCP73812 - PROG = 20 kΩ

— 100 — mA MCP73812 - PROG = 10 kΩ

— 500 — mA MCP73812 - PROG = 2 kΩ

Charge Current Tolerance I

RTOL

-10 — +10 % TA=-5°C to +55°C

Pass Transistor ON-Resistance

ON-Resistance R

DSON

— 400 — mΩ VDD = 3.75V, TJ = 105°C

Battery Discharge Current

Output Reverse Leakage I

DISCHARGE

Current — 0.5 2 µA Shutdown

(typ.) + 0.3V] to 6V,

REG

SS

< V

(V

I

OUT

I

OUT

V

OUT

(V

DD

- 100 mV)

BAT

=[V

(Typ)+1V]

REG

=10 mA

=[V

(Typ)+1V] to 6V

REG

=10 mA

=10 mA to 50 mA

=[V

(Typ)+1V]

REG

=10 mA, 10 Hz to 1 kHz

=10 mA, 10 Hz to 10 kHz

=10 mA, 10 Hz to 1 MHz

< V

- 100 mV)

BAT

)

MCP73811/2

DC CHARACTERISTICS (Continued)

Electrical Specifications: Unless otherwise indicated, all limits apply for VDD= [V

T

= -40°C to +85°C. Typical values are at +25°C, V

A

Parameters Sym Min Typ Max Units Conditions

Charge Enable (CE), PROG Input - MCP73811

Input High Voltage Level V

Input Low Voltage Level V

Input Leakage Current I

IH

IL

LK

PROG Input - MCP73812

Charge Impedance Range R

PROG

Automatic Power Down (Direction Control)

Automatic Power Down Entry Threshold

Automatic Power Down

V

PDEXIT

PD

Exit Threshold

Thermal Shutdown

Die Temperature T

SD

SDHYS

Hysteresis

= [V

DD

(typ.) + 1.0V]

REG

2——V

——0.8V

—0.01 1µAV

2—20kΩ MCP73812

V

+

BAT

10 mV

—V

V

BAT

50 mV

BAT

+

150 mV

— 150 — °C

—10—°C

(typ.) + 0.3V] to 6V,

REG

— V 2.3V < V

VDD Falling

V

+

BAT

250 mV

V2.3V < V

VDD Rising

= VDD, V

CE

BAT

PROG

< V

REG

= V

DD

TEMPERATURE SPECIFICATIONS

Electrical Specifications: Unless otherwise indicated, all limits apply for V

Typical values are at +25°C, V

Parameters Sym Min Typ Max Units Conditions

Temperature Ranges

Specified Temperature Range T

Operating Temperature Range T

Storage Temperature Range T

Thermal Package Resistances

Thermal Resistance, 5-Lead, SOT-23 θ

DD

= [V

(typ.) + 1.0V]

REG

A

J

A

JA

-40 — +85 °C

-40 — +125 °C

-65 — +150 °C

— 230 — °C/W 4-Layer JC51-7 Standard Board,

DD

= [V

(typ.) + 0.3V] to 6V.

REG

Natural Convection

MCP73811/2

4.170

4.175

4.180

4.185

4.190

4.195

4.200

4.205

4.210

4.50 4.75 5.00 5.25 5.50 5.75 6.00

Supply Voltage (V)

Battery Regulation Voltage

(V)

I

OUT

= 10 mA

I

OUT

= 100 mA

I

OUT

= 450 mA

4.170

4.175

4.180

4.185

4.190

4.195

4.200

4.205

4.210

-40

-30

-20

-10

0

10203040506070

80

Ambient Temperature (°C)

Battery Regulation Voltage (V)

I

OUT

= 10 mA

I

OUT

= 100 mA

I

OUT

= 450 mA

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

3.00 3.20 3.40 3.60 3.80 4.00 4.20

Battery Regulation Voltage (V)

Output Leakage Current (µA)

+85°C

-40°C

+25°C

80

81

82

83

84

85

86

87

88

89

90

4.5 4.75 5 5.25 5.5 5.75 6

Supply Voltage (V)

Charge Current (mA)

PROG = Low

Temp = +25°C

425

430

435

440

445

450

455

460

4.5 4.75 5 5.25 5.5 5.75 6

Supply Voltage (V)

Charge Current (mA)

Temp = 25°C

65

70

75

80

85

90

95

100

-40-30-20-10 0 1020304050607080

Ambient Temperature (°C)

Charge Current (mA)

V

DD

V

2.0 TYPICAL PERFORMANCE CURVES

Note: The graphs and tables provided following this note are a statistical summary based on a limited number of

samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range.

Note: Unless otherwise indicated, VDD = [V

(typ.) + 1V], I

REG

= 10 mA and TA= +25°C, Constant-voltage mode.

OUT

FIGURE 2-1: Battery Regulation Voltage (V

) vs. Supply Voltage (VDD).

BAT

FIGURE 2-2: Battery Regulation Voltage

) vs. Ambient Temperature (TA).

(V

BAT

FIGURE 2-4: Charge Current (I Supply Voltage (V

) - MCP73811.

DD

PROG = High

FIGURE 2-5: Charge Current (I Supply Voltage (V

) - MCP73811.

DD

PROG = Low

OUT

) vs.

= 5

FIGURE 2-3: Output Leakage Current (I

DISCHARGE

(V

).

BAT

) vs. Battery Regulation Voltage

FIGURE 2-6: Charge Current (I Ambient Temperature (T

) - MCP73811.

A

OUT

) vs.

MCP73811/2

400

410

420

430

440

450

460

470

480

-40-30-20-10 0 1020304050607080

Ambient Temperature (°C)

Charge Current (mA)

VDD = 5V

0

50

100

150

200

250

300

350

400

450

500

550

2 4 6 8 10 12 14 16 18 20

Programming Resistor (kΩ)

Charge Current (mA)

96

97

98

99

100

101

102

103

104

4.50 4.75 5.00 5.25 5.50 5.75 6.00

Supply Voltage (V)

Charge Current (mA)

R

PROG

= 10 kΩ

500

502

504

506

508

510

512

514

516

4.50 4.75 5.00 5.25 5.50 5.75 6.00

Supply Voltage (V)

Charge Current (mA)

R

PROG

= 2 kΩ

96

97

98

99

100

101

102

103

104

-40

-30

-20

-10

0

10203040506070

80

Ambient Temperature (°C)

Charge Current (mA)

R

PROG

= 10 kΩ

500

502

504

506

508

510

512

514

516

-40

-30

-20

-10

0

10203040506070

80

Ambient Temperature (°C)

Charge Current (mA)

R

PROG

= 2 kΩ

Typical Performance Curves (Continued)

Note: Unless otherwise indicated, VDD = [V

PROG = High

FIGURE 2-7: Charge Current (I Ambient Temperature (T

) - MCP73811.

A

(typ.) + 1V], I

REG

) vs.

OUT

= 10 mA and TA= +25°C, Constant-voltage mode.

OUT

FIGURE 2-10: Charge Current (I Supply Voltage (V

) - MCP73812.

DD

OUT

) vs.

FIGURE 2-8: Charge Current (I Programming Resistor (R

FIGURE 2-9: Charge Current (I Supply Voltage (V

DD

) - MCP73812.

PROG

) - MCP73812.

OUT

) vs.

FIGURE 2-11: Charge Current (I Ambient Temperature (T

) - MCP73812.

A

FIGURE 2-12: Charge Current (I Ambient Temperature (T

) - MCP73812.

A

OUT

) vs.

Typical Performance Curves (Continued)

0

15

30

45

60

75

90

105

120

25354555657585

95

105

115

125

135

145

155

Junction Temperature (°C)

Charge Current (mA)

R

PROG

0

75

150

225

300

375

450

525

25354555657585

95

105

115

125

135

145

155

Junction Temperature (°C)

Charge Current (mA)

R

PROG

= 2 kΩ

-60

-50

-40

-30

-20

-10

0

0.01 0.1 1 10 100 1000

Frequency (kHz)

Attenuation (dB)

VAC = 100 mVp-p I

OUT

= 10 mA

C

OUT

= 4.7 μF, X7R

Ceramic

-60

-50

-40

-30

-20

-10

0

0.01 0.1 1 10 100 1000

Frequency (kHz)

Attenuation (dB)

VAC = 100 mVp-p I

OUT

= 100 mA

C

OUT

= 4.7 µF, X7R

Ceramic

-2

0

2

4

6

8

10

12

14

0

204060

80

100

120

140

160

180

200

Time (µs)

Source Voltage (V)

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

Output Ripple (V)

I

OUT

= 10 mA

C

OUT

= 4.7 µF, X7R

Ceramic

-2

0

2

4

6

8

10

12

14

0

204060

80

100

120

140

160

180

200

Time (µs)

Source Voltage (V)

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

Output Ripple (V)

I

OUT

= 100 mA

C

OUT

= 4.7 µF, X7R

Ceramic

MCP73811/2

Note: Unless otherwise indicated, VDD = [V

FIGURE 2-13: Charge Current (I Junction Temperature (T

) - MCP73812.

J

(typ.) + 1V], I

REG

= 10 kΩ

) vs.

OUT

= 10 mA and TA= +25°C, Constant-voltage mode.

OUT

FIGURE 2-16: Power Supply Ripple Rejection (PSRR).

FIGURE 2-14: Charge Current (I Junction Temperature (T

FIGURE 2-15: Power Supply Ripple Rejection (PSRR).

) - MCP73812.

J

OUT

) vs.

FIGURE 2-17: Line Transient Response.

FIGURE 2-18: Line Transient Response.

MCP73811/2

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0

204060

80

100

120

140

160

180

200

Time (µs)

Output Current (A)

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

0.04

Output Ripple (V)

C

OUT

= 4.7 µF, X7R

Ceramic

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0

204060

80

100

120

140

160

180

200

Time (µs)

Output Current (A)

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

Output Ripple (V)

C

OUT

= 4.7 µF, X7R

Ceramic

0.0

1.0

2.0

3.0

4.0

5.0

0

1530456075

90

105

120

135

150

165

180

Time (Minutes)

Battery Voltage (V)

Charge Current (mA)

0

100

200

300

400

500

MCP73812T-420I/OT V

DD

= 5.0V

R

PROG

= 2 kΩ

Typical Performance Curves (Continued)

Note: Unless otherwise indicated, VDD = [V

(typ.) + 1V], I

REG

FIGURE 2-19: Load Transient Response.

= 10 mA and TA= +25°C, Constant-voltage mode.

OUT

FIGURE 2-21: Typical Charge Profile (950 mAh) Li-Ion Battery.

FIGURE 2-20: Load Transient Response.

3.0 PIN DESCRIPTION

The descriptions of the pins are listed in Table 3-1.

TABLE 3-1: PIN FUNCTION TABLES

MCP73811/2

Pin Number

SOT-23-5

1 CE Active High Charge Enable

2V

3V

4V

5 PROG Current Regulation Set and Charge Control Enable

Symbol Function

SS

BAT

DD

Battery Management 0V Reference

Battery Charge Control Output

Battery Management Input Supply

3.1 Charge Enable Input (CE)

A logic High enables battery charging. A logic Low disables battery charging. The charge enable input is compatible with 1.8V logic.

3.2 Battery Management 0V Reference

)

(V

SS

Connect to negative terminal of battery and input supply.

3.3 Battery Charge Control Output

(V

)

BAT

Connect to positive terminal of battery. Drain terminal of internal P-channel MOSFET pass transistor. Bypass to VSS with a minimum of 1 µF to ensure loop stability when the battery is disconnected.

3.4 Battery Management Input Supply (V

)

DD

A supply voltage of [V recommended. Bypass to VSS with a minimum of 1 µF.

(typ.) + 0.3V] to 6V is

REG

3.5 Current Regulation Set (PROG)

For the MCP73811, the current regulation set input (PROG) functions as a digital input selection. A logic Low selects a 85 mA charge current; a logic High selects a 450 mA charge current.

For the MCP73812, the charge current is set by placing a resistor from PROG to V

SS

.

MCP73811/2

SHUTDOWN MODE*

V

DD

< V

PD

CONSTANT CURRENT

MODE

Charge Current = I

REG

CONSTANT VOLTAGE

MODE

Charge Voltage = V

REG

* Continuously Monitored

V

BAT

= V

REG

STANDBY MODE*

CE = Low

V

BAT

< V

REG

I

REG

1000V

R

PROG

---------------- -=

Where:

R

PROG

= kilo-ohms

I

REG

= milliamperes

4.0 DEVICE OVERVIEW

The MCP73811/2 are simple, but fully integrated linear charge management controllers. Figure 4-1 depicts the operational flow algorithm.

4.3 PRECONDITIONING

The MCP73811/2 does not support preconditioning of deeply depleted cells.

4.4 Constant Current MODE - Fast Charge

During the constant current mode, the selected (MCP73811) or programmed (MCP73812) charge current is supplied to the battery or load.

For the MCP73812, the charge current is established using a single resistor from PROG to V resistor and the charge current are calculated using the following equation:

EQUATION 4-1:

Constant current mode is maintained until the voltage at the V

pin reaches the regulation voltage, V

BAT

. The program

SS

REG

.

4.5 Constant Voltage Mode

FIGURE 4-1: Flow Chart.

When the voltage at the V regulation voltage, V

, constant voltage regulation

REG

begins. The regulation voltage is factory set to 4.20V with a tolerance of ±1.0%.

pin reaches the

BAT

4.1 Undervoltage Lockout (UVLO)

The MCP73811/2 does not have an internal under voltage lockout (UVLO) circuit.

4.2 Charge Qualification

When the input power is applied, the input supply must

BAT

rise 150 mV above the battery voltage before the MCP73811/2 becomes operational.

The automatic power down circuit places the device in a shutdown mode if the input supply falls to within +50 mV of the battery voltage.

The automatic circuit is always active. Whenever the input supply is within +50 mV of the voltage at the V pin, the MCP73811/2 is placed in a shutdown mode.

During power down condition, the battery reverse discharge current is less than 2 µA.

For a charge cycle to begin, the automatic power down conditions must be met and the charge enable input must be above the input high threshold.

4.6 Charge Termination

The charge cycle is terminated by removing the battery from the charger, removing input power, or driving the charge enable input (CE) to a logic Low. An automatic charge termination method is not implemented.

4.7 Automatic Recharge

The MCP73811/2 does not support automatic recharge cycles since automatic charge termination has not been implemented. In essence, the MCP73811/2 is always in a charge cycle whenever the qualification parameters have been met.

MCP73811/2

0

75

150

225

300

375

450

525

25354555657585

95

105

115

125

135

145

155

Junction Temperature (°C)

Charge Current (mA)

R

PROG

= 2 kΩ

4.8 Thermal Regulation

The MCP73811/2 limits the charge current based on the die temperature. The thermal regulation optimizes the charge cycle time while maintaining device reliability. Figure 4-2 depicts the thermal regulation for the MCP73811/2.

.

FIGURE 4-2: Thermal Regulation.

4.9 Thermal Shutdown

The MCP73811/2 suspends charge if the die temperature exceeds 150°C. Charging will resume when the die temperature has cooled by approximately 10°C. The thermal shutdown is a secondary safety feature in the event that there is a failure within the thermal regulation circuitry.

MCP73811/2

I

REG

1000V

R

PROG

---------------- -=

Where:

R

PROG

= kilo-ohms

I

REG

= milliamperes

5.0 DETAILED DESCRIPTION

5.1 Analog Circuitry

5.1.1 BATTERY MANAGEMENT INPUT SUPPLY (V

The VDD input is the input supply to the MCP73811/2. The MCP73811/2 automatically enters a Power-down mode if the voltage on the VDD input falls to within +50 mV of the battery voltage. This feature prevents draining the battery pack when the V present.

5.1.2 MCP73812 CURRENT REGULATION SET (PROG)

For the MCP73812, the charge current regulation can be scaled by placing a programming resistor (R from the PROG input to VSS. The program resistor and the charge current are calculated using the following equation:

EQUATION 5-1:

DD

)

supply is not

DD

PROG

5.2 Digital Circuitry

5.2.1 CHARGE ENABLE (CE)

The charge enable input pin (CE) can be used to terminate a charge at any time during the charge cycle, as well as to initiate a charge cycle or initiate a recharge cycle.

Driving the input to a logic High enables the device. Driving the input to a logic Low disables the device and terminates a charge cycle. When disabled, the device’s supply current is reduced to 50 µA, typically.

5.2.2 MCP73811 CURRENT REGULATION SELECT (PROG)

For the MCP73811, driving the PROG input to a logic Low selects the low charge current setting (85 mA).

)

Driving the PROG input to a logic High selects the high charge current setting (450 mA).

5.1.3 BATTERY CHARGE CONTROL OUTPUT (V

The battery charge control output is the drain terminal of an internal P-channel MOSFET. The MCP73811/2 provides constant current and voltage regulation to the battery pack by controlling this MOSFET in the linear region. The battery charge control output should be connected to the positive terminal of the battery pack.

BAT

)

MCP73811/2

CE

V

DD

V

SS

PROG

V

BAT

+

-

Single Li-Ion Cell

4

MCP73812

5

3

1

C

IN

Li-Ion Battery Charger

2

R

PROG

C

OUT

REGULATED WALL CUBE

0.0

1.0

2.0

3.0

4.0

5.0

0

1530456075

90

105

120

135

150

165

180

Time (Minutes)

Battery Voltage (V)

Charge Current (mA)

0

100

200

300

400

500

MCP73812T-420I/OT V

DD

= 5.0V

R

PROG

= 2 kΩ

6.0 APPLICATIONS

The MCP73811/2 is designed to operate in conjunction with a host microcontroller or in stand-alone applications. The MCP73811/2 provides the preferred

FIGURE 6-1: Typical Application Circuit.

charge algorithm for Lithium-Ion and Lithium-Polymer cells Constant-current followed by Constant-voltage.

Figure 6-1 depicts a typical stand-alone application

circuit, while Figures 6-2 depict the accompanying charge profile.

6.1 Application Circuit Design

Due to the low efficiency of linear charging, the most important factors are thermal design and cost, which are a direct function of the input voltage, output current and thermal impedance between the battery charger and the ambient cooling air. The worst-case situation is when the device has transitioned from the Preconditioning mode to the Constant-current mode. In this situation, the battery charger has to dissipate the maximum power. A trade-off must be made between the charge current, cost and thermal requirements of the charger.

6.1.1 COMPONENT SELECTION

FIGURE 6-2: Typical Charge Profile (950 mAh Li-Ion Battery).

Selection of the external components in Figure 6-1 is crucial to the integrity and reliability of the charging system. The following discussion is intended as a guide for the component selection process.

6.1.1.1 Charge Current

The preferred fast charge current for Lithium-Ion cells is at the 1C rate, with an absolute maximum current at the 2C rate. For example, a 500 mAh battery pack has a preferred fast charge current of 500 mA. Charging at this rate provides the shortest charge cycle times without degradation to the battery pack performance or life.

MCP73811/2

PowerDissipation V

DDMAXVPTHMIN

–()I

REGMAX

×=

Where:

V

DDMAX

= the maximum input voltage

I

REGMAX

= the maximum fast charge current

V

PTHMIN

= the minimum transition threshold

voltage

PowerDissipation 5.5V 2.7V–()500mA

×

1.4W==

C

OUT

R

PROG

C

IN

MCP73812

V

BAT

V

DD

V

SS

V

BAT

V

SS

V

DD

6.1.1.2 Thermal Considerations

The worst-case power dissipation in the battery charger occurs when the input voltage is at the maximum and the device has transitioned from the Preconditioning mode to the Constant-current mode. In this case, the power dissipation is:

EQUATION 6-1:

Power dissipation with a 5V, ±10% input voltage source is:

EQUATION 6-2:

This power dissipation with the battery charger in the SOT-23-5 package will cause thermal regulation to be entered as depicted in Figure 6-3.

6.1.1.4 Reverse-Blocking Protection

The MCP73811/2 provides protection from a faulted or shorted input. Without the protection, a faulted or shorted input would discharge the battery pack through the body diode of the internal pass transistor.

6.1.1.5 Charge Inhibit

The charge enable input pin (CE) can be used to terminate a charge at any time during the charge cycle, as well as to initiate a charge cycle or initiate a recharge cycle.

Driving the input to a logic High enables the device. Driving the input to a logic Low disables the device and terminates a charge cycle. When disabled, the device’s supply current is reduced to 50 µA, typically.

6.2 PCB Layout Issues

For optimum voltage regulation, place the battery pack as close as possible to the device’s V recommended to minimize voltage drops along the high current-carrying PCB traces.

If the PCB layout is used as a heatsink, adding many vias in the heatsink pad can help conduct more heat to the backplane of the PCB, thus reducing the maximum junction temperature. Figures 6-3 and 6-4 depict a typical layout with PCB heatsinking.

and VSS pins,

BAT

6.1.1.3 External Capacitors

The MCP73811/2 is stable with or without a battery load. In order to maintain good AC stability in the Constant-voltage mode, a minimum capacitance of 1 µF is recommended to bypass the V This capacitance provides compensation when there is no battery load. In addition, the battery and interconnections appear inductive at high frequencies. These elements are in the control feedback loop during Constant-voltage mode. Therefore, the bypass capacitance may be necessary to compensate for the inductive nature of the battery pack.

Virtually any good quality output filter capacitor can be used, independent of the capacitor’s minimum Effective Series Resistance (ESR) value. The actual value of the capacitor (and its associated ESR) depends on the output load current. A 1 µF ceramic, tantalum or aluminum electrolytic capacitor at the output is usually sufficient to ensure stability for output currents up to a 500 mA.

pin to VSS.

BAT

FIGURE 6-3: Typical Layout (Top).

FIGURE 6-4: Typical Layout (Bottom).

7.0 PACKAGE INFORMATION

5-Pin SOT-23

XXNN

Standard *

Part Number Code

MCP73811T-420I/OT KSNN MCP73812T-420I/OT KWNN

Example:

Legend: XX...X Customer-specific information

Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘01’) NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) * This package is Pb-free. The Pb-free JEDEC designator ( )

can be found on the outer packaging for this package.

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line, thus limiting the number of available characters for customer-specific information.

3

e

1

KSNN

1

* Custom output voltages available upon request.

Contact your local Microchip sales office for more information.

7.1 Package Marking Information

MCP73811/2

3

e

MCP73811/2

5-Lead Plastic Small Outline Transistor (OT) [SOT-23]

Notes:

1. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.127 mm per side.

2. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances.

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

Units MILLIMETERS

Dimension Limits MIN NOM MAX Number of Pins N 5 Lead Pitch e 0.95 BSC Outside Lead Pitch e1 1.90 BSC Overall Height A 0.90 – 1.45 Molded Package Thickness A2 0.89 – 1.30 Standoff A1 0.00 – 0.15 Overall Width E 2.20 – 3.20 Molded Package Width E1 1.30 – 1.80 Overall Length D 2.70 – 3.10 Foot Length L 0.10 – 0.60 Footprint L1 0.35 – 0.80 Foot Angle φ 0° – 30° Lead Thickness c 0.08 – 0.26 Lead Width b 0.20 – 0.51

φ

N

b

E

E1

D

1

2

3

e

e1

A

A1

A2

c

L

L1

Microchip Technology Drawing C04-091B

APPENDIX A: REVISION HISTORY

Revision B (September 2007)

The following is the list of modifications:

1. Modified “No End-of-Charge Control” bullet to read “External End-of-Charge Control”.

2. Deleted No Undervoltage Lockout (UVLO) bullet

3. Replaced Figure 2-21 with new plot and changed figure caption.

4. Deleted Figure 2-22.

5. Replaced Figure 6-2 with new plot and changed figure caption.

6. Deleted Figure 6-3.

7. Updated revision history.

Revision A (March 2007)

• Original Release of this Document.

MCP73811/2

NOTES:

MCP73811/2

Device: MCP73811T: Li-Ion Charger w/Selectable Charge Current,

Tape and Reel

MCP73812T: Li-Ion Charger w/Selectable Charge Current,

Tape and Reel

Voltage Options *: 420 = 4.2V “Standard”

*Contact factory for other output voltage options.

Temperature: I = -40°C to +85°C

Package Type: OT = Small Outline Transistor (SOT-23), 5-lead

PART NO. XXX

Vol tag e

Device

Options

X

Temp eratu re

/XX

Package

Examples:

a) MCP73811T-420I/OT: 4.2V Charger

SOT-23-5 pkg.

a) MCP73812T-420I/OT: 4.2V Charger

SOT-23-5 pkg.

—

PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

MCP73811/2

NOTES:

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Information contained in this publication regarding device

applications and the like is provided only for your convenience

and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR

WARRANTIES OF ANY KIND WHETHER EXPRESS OR

IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION,

INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip

devices in life support and/or safety applications is entirely at

the buyer’s risk, and the buyer agrees to defend, indemnify and

hold harmless Microchip from any and all damages, claims,

suits, or expenses resulting from such use. No licenses are

conveyed, implicitly or otherwise, under any Microchip intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, Accuron, dsPIC, K

EELOQ, KEELOQ logo, microID, MPLAB, PIC,

PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

AmpLab, FilterLab, Linear Active Thermistor, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A.

Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.

All other trademarks mentioned herein are property of their respective companies.

Printed on recycled paper.

Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.

®

MCUs and dsPIC® DSCs, KEELOQ

®

code hopping

WORLDWIDE SALES AND SERVICE

AMERICAS

Corporate Office

2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://support.microchip.com Web Address: www.microchip.com

Atlanta

Duluth, GA Tel: 678-957-9614 Fax: 678-957-1455

Boston

Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088

Chicago

Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075

Dallas

Addison, TX Tel: 972-818-7423 Fax: 972-818-2924

Detroit

Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260

Kokomo

Kokomo, IN Tel: 765-864-8360 Fax: 765-864-8387

Los Angeles

Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608

Santa Clara

Santa Clara, CA Tel: 408-961-6444 Fax: 408-961-6445

Toronto

Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509

ASIA/PACIFIC

Asia Pacific Office

Suites 3707-14, 37th Floor Tower 6, The Gateway Harbour City, Kowloon Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431

Australia - Sydney

Tel: 61-2-9868-6733 Fax: 61-2-9868-6755

China - Beijing

Tel: 86-10-8528-2100 Fax: 86-10-8528-2104

China - Chengdu

Tel: 86-28-8665-5511 Fax: 86-28-8665-7889

China - Fuzhou

Tel: 86-591-8750-3506 Fax: 86-591-8750-3521

China - Hong Kong SAR

Tel: 852-2401-1200 Fax: 852-2401-3431

China - Qingdao

Tel: 86-532-8502-7355 Fax: 86-532-8502-7205

China - Shanghai

Tel: 86-21-5407-5533 Fax: 86-21-5407-5066

China - Shenyang

Tel: 86-24-2334-2829 Fax: 86-24-2334-2393

China - Shenzhen

Tel: 86-755-8203-2660 Fax: 86-755-8203-1760

China - Shunde

Tel: 86-757-2839-5507 Fax: 86-757-2839-5571

China - Wuhan

Tel: 86-27-5980-5300 Fax: 86-27-5980-5118

China - Xian

Tel: 86-29-8833-7252 Fax: 86-29-8833-7256

ASIA/PACIFIC

India - Bangalore

Tel: 91-80-4182-8400 Fax: 91-80-4182-8422

India - New Delhi

Tel: 91-11-4160-8631 Fax: 91-11-4160-8632

India - Pune

Tel: 91-20-2566-1512 Fax: 91-20-2566-1513

Japan - Yokohama

Tel: 81-45-471- 6166 Fax: 81-45-471-6122

Korea - Daegu

Tel: 82-53-744-4301 Fax: 82-53-744-4302

Korea - Seoul

Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934

Malaysia - Penang

Tel: 60-4-646-8870 Fax: 60-4-646-5086

Philippines - Manila

Tel: 63-2-634-9065 Fax: 63-2-634-9069

Singapore

Tel: 65-6334-8870 Fax: 65-6334-8850

Taiwan - Hsin Chu

Tel: 886-3-572-9526 Fax: 886-3-572-6459

Taiwan - Kaohsiung

Tel: 886-7-536-4818 Fax: 886-7-536-4803

Taiwan - Taipei

Tel: 886-2-2500-6610 Fax: 886-2-2508-0102

Thailand - Bangkok

Tel: 66-2-694-1351 Fax: 66-2-694-1350

EUROPE

Austria - Wels

Tel: 43-7242-2244-39 Fax: 43-7242-2244-393

Denmark - Copenhagen

Tel: 45-4450-2828 Fax: 45-4485-2829

France - Paris

Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79

Germany - Munich

Tel: 49-89-627-144-0 Fax: 49-89-627-144-44

Italy - Milan

Tel: 39-0331-742611 Fax: 39-0331-466781

Netherlands - Drunen

Tel: 31-416-690399 Fax: 31-416-690340

Spain - Madrid

Tel: 34-91-708-08-90 Fax: 34-91-708-08-91

UK - Wokingham

Tel: 44-118-921-5869 Fax: 44-118-921-5820

06/25/07

MICROCHIP MCP73811, MCP73812 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual

2.0 TYPICAL PERFORMANCE CURVES

3.0 PIN DESCRIPTION

4.0 DEVICE OVERVIEW

5.0 DETAILED DESCRIPTION

6.0 APPLICATIONS

7.0 PACKAGE INFORMATION