© 2007 Microchip Technology Inc. DS22071A-page 1
MCP73837/8
Features
• High Accuracy Preset Voltage Regulation: + 0.5%
• Available Voltage Regulation Options:
- 4.20V, 4.35V, 4.4V, or 4.5V
• Complete Linear Charge Management Controller:
- Autonomous Power Source Selection
- Integrated Pass Transistors
- Integrated Current Sense
- Integrated Reverse Discharge Protection
• Constant Current (CC) / Constant Voltage (CV)
Operation with Thermal Regulation
• Selectable USB-Port Charge Current:
- Low: 1 Unit Load / High: 5 Unit Loads
• Programmable AC-Adapter Charge Current:
- 15mA - 1000mA
• Two Charge Status Outputs
• Power-Good Monitor: MCP73837
• Timer Enable: MCP73838
• Automatic Recharge:
- Selectable Voltage Threshold
• Automatic End-of-Charge Control:
- Selectable Charge Termination Current Ratio
- Selectable Safety Timer Period
• Preconditioning of Deeply Depleted Cells - can be
disabled
• Battery Cell Temperature Monitor
• UVLO (Undervoltage Lockout)
• Automatic Power-Down when Input Power is
Removed
• Low-Dropout (LDO) Linear Regulator Mode
• Numerous Selectable Options Available for a
Variety of Applications:
- Refer to Section 1.0 “Electrical
Characteristics” for Selectable Options”
- Refer to the “Product Identification
System” for Standard Options
• Temperature Range: -40°C to 85°C
• Packaging:
- 10-Lead 3 mm x 3 mm DFN
- 10-Lead MSOP*
* Consult Factory for MSOP Package
Availability.
Applications
• Smart Phones and Personal Data Assistants
(PDA)
• Portable Media Players(PMP)
• Ultra Mobile Devices(UMD)
• Digital Cameras
• MP3 Players
• Bluetooth Headsets
• Handheld Medical Devices
• AC/USB Dual Source Li-Ion Battery Chargers
Description
The MCP73837 and MCP73838 devices are fully
integrated linear Li-Ion / Li-Polymer battery chargers
with autonomous power source selection. Along with its
small physical size, the low number of external
components required makes the MCP73837/8 ideally
suitable for portable applications.
The MCP73837/8 automatically selects the USB-Port
or AC-Adapter as the power source for the system. For
the USB-Port powered systems, the MCP73837/8
specifically adheres to the current limits governed by
the USB specification. The host microcontroller can
select from two preset maximum charge current rates
of 100 mA (low power USB-port) or 500 mA (high
power USB-port). With an AC-Adapter providing power
to the system, an external resistor sets the magnitude
of the system or charge current up to a maximum of 1A.
The MCP73837/8 employs a constant current /
constant voltage charge algorithm with selectable
preconditioning and charge termination. The constant
voltage regulation is fixed with four available options:
4.20V, 4.35V, 4.40V, or 4.50V, to accommodated the
new emerging battery charging requirements. The
MCP73837/8 limits the charge current based on die
temperature during high power or high ambient
conditions. This thermal regulation optimizes the
charge cycle time while maintaining the device
reliability.
The MCP73837/8 are fully specified over the ambient
temperature range of -40°C to +85°C.
The MCP73837/8 devices are available in a 10-Lead,
3 mm x 3 mm, DFN package or in a 10-Lead MSOP
package.
Advanced Stand-Alone Li-Ion / Li-Polymer Battery Charge
Management Controller with Autonomous AC-Adapter or
USB-Port Source Selection
