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DS2775, DS2776, DS2777, DS2778
2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication
Industry's Smallest 2-Cell, Stand-Alone Fuel Gauge to Integrate an Li+ Protector and SHA-1 Authentication
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Status
Active: In Production.
Description
The DS2775–DS2778 report available capacity for rechargeable lithium-ion (Li+) and Li+ polymer (Li-Poly) batteries in mAh and as a percentage of full. Safe operation is ensured by the integrated Li+ protector. The DS2776/DS2778 support SHA-1-based challenge-response authentication in addition to all other DS2775/DS2777 features.
Precision measurements of voltage, temperature, and current, along with a cell characteristics table and application parameters, are used for capacity estimation calculations. The capacity registers report a conservative estimate of the amount of charge that can be removed given the current temperature, discharge rate, stored charge, and application parameters.
The DS2775–DS2778 operate from +4.0V to +9.2V for direct integration into battery packs with two Li+ or Li- Poly cells.
In addition to nonvolatile storage for cell compensation and application parameters, the DS2775–DS2778 offer 16 bytes of EEPROM for use by the host system and/or pack manufacturer to store battery lot and date tracking information. The EEPROM can also be used for nonvolatile storage of system and/or battery usage statistics. A Maxim 1-Wire® (DS2775/DS2776) or 2-wire (DS2777/DS2778) interface provides serial communication to access measurement and capacity data registers, control registers, and user memory. The DS2776/DS2778 use the SHA-1 hash algorithm in a challenge-response pack authentication protocol for battery-pack verification.
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Data Sheet
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An evaluation kit is available: DS2775EVKIT, DS2776EVKIT, DS2777EVKIT, DS2778EVKIT NOTE: This product uses the following:DS2775–DS2778 Evaluation Kit Software
Key Features
- High-Side nFET Drivers and Protection Circuitry
- Precision Voltage, Temperature, and Current Measurement System
- Cell-Capacity Estimation from Coulomb Count, Discharge Rate, Temperature, and Cell Characteristics
- Estimates Cell Aging Between Learn Cycles
- Uses Low-Cost Sense Resistor
- Allows Calibration of Gain and Temperature Coefficient
- Programmable Thresholds for Overvoltage and Overcurrent
- Pack Authentication Using SHA-1 Algorithm (DS2776/DS2778)
- 32-Byte Parameter EEPROM
- 16-Byte User EEPROM
- Maxim 1-Wire Interface with 64-Bit Unique ID (DS2775/DS2776)
- 2-Wire Interface with 64-Bit Unique ID (DS2777/DS2778)
- 3mm x 5mm, 14-pin TDFN Lead-Free Package
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Applications/Uses
- Commercial and Military Radios
- DSLR Cameras
- Low-Cost Notebooks
- Portable Medical Equipment
- UMPCs
- Video Cameras
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Key Specifications:
| Battery Protectors, Selectors and Monitors |
| Part Number |
Functions |
Battery Type |
Interface |
User Data Storage
(Bytes) |
Parameters Measured |
Battery Protection |
VSUPPLY
(V) |
VSUPPLY
(V) |
Package/Pins |
Smallest Available Pckg.
(mm2) |
Oper. Temp.
(°C) |
Budgetary Price |
| min |
max |
max w/pins |
See Notes |
| DS2775 |
| Fuel Gauge | | Protector | | Status Monitor |
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2 Cell Li-Ion |
1-Wire |
16 EEPROM |
| Current | | Temperature | | Time | | Voltage |
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| Over Voltage | | Over-Current | | Over/Under Voltage |
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4 |
9.2 |
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15 |
-20 to +70 |
$2.94 @1k |
| DS2776 |
1-Wire |
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$3.16 @1k |
| DS2777 |
2-Wire |
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$3.43 @1k |
| DS2778 |
2-Wire |
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$3.16 @1k |
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See All Battery Protectors, Selectors and Monitors (29)
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Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
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Diagram
Typical Application Circuits
Reliability Reports
Software/Models
Ordering Information
Notes:
- Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
- Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
- Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
- * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
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Information Index
Document Ref.: 19-4688
Rev 4;
2011-06-10
This page last modified: 2011-06-10
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