Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - battery management Battery monitoring Li-Ion TSSOP 16 Surface-mount

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REV: 010906

Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device

may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata

GENERAL DESCRIPTION

The DS2762 high-precision Li+ battery monitor is a

data-acquisition, information-storage, and safety-

protection device tailored for cost-sensitive battery

pack applications. This low-power device integrates

precise temperature, voltage, and current

measurement, nonvolatile (NV) data storage, and Li+

protection into the small footprint of either a TSSOP

package or flip-chip package. The DS2762 is a key

component in applications including remaining

capacity estimation, safety monitoring, and battery-

specific data storage.

PIN CONFIGURATIONS

FEATURES

§ Li+ Safety Circuit

Overvoltage Protection

Overcurrent/Short-Circuit Protection

Undervoltage Protection

§ Host Alerted When Accumulated Current or

Temperature Exceeds User-Selectable Limits

§ 0V Battery Recovery Charge

§ Available in Two Configurations:

Internal 25mW Sense Resistor

External User-Selectable Sense Resistor

§ Current Measurement

12-Bit Bidirectional Measurement

Internal Sense Resistor Configuration:

0.625mA LSB and ±1.9A Dynamic Range

External Sense Resistor Configuration:

15.625mV LSB and ±64mV Dynamic Range

§ Current Accumulation:

Internal Sense Resistor: 0.25mAhr LSB

External Sense Resistor: 6.25mVhr LSB

§ Voltage Measurement with 4.88mV Resolution

§ Temperature Measurement Using Integrated

Sensor with 0.125°C Resolution

§ System Power Management and Control

Feature Support

§ 32 Bytes of Lockable EEPROM

§ 16 Bytes of General-Purpose SRAM

§ Dallas 1-Wire

Interface with Unique 64-Bit

Device Address

§ Low-Power Consumption:

Active Current: 60mA typ, 90mA max

Sleep Current: 1mA typ, 2mA max

APPLICATIONS

PDAs

Cell Phones/Smartphones

Digital Cameras

ORDERING INFORMATION

PART TEMP RANGE PIN-PACKAGE

DS2762BE+ -20°C to +70°C 16 TSSOP

Selector Guide appears at end of data sheet, for additional

options.

DS2762

High-Precision Li+ Battery Monitor With Alerts

www.maxim-ic.com

TOP VIEW

PIO

IS1

TSSOP

IS2

SNS

PLS

1-Wire is registered trademark of Dallas Semiconductor.

FLIP CHIP

(top view – bumps on bottom)

PLS DC DQ

C IS2

IS1

PIO P

SNS

1 2 3 4

SNS

PROBE

Summary of content (25 pages)

PAGE 1
DS2762 High-Precision Li+ Battery Monitor With Alerts www.maxim-ic.com FEATURES GENERAL DESCRIPTION The DS2762 high-precision Li+ battery monitor is a data-acquisition, information-storage, and safetyprotection device tailored for cost-sensitive battery pack applications. This low-power device integrates precise temperature, voltage, and current measurement, nonvolatile (NV) data storage, and Li+ protection into the small footprint of either a TSSOP package or flip-chip package.
PAGE 2
DS2762 High-Precision Li+ Battery Monitor With Alerts ABSOLUTE MAXIMUM RATINGS Voltage Range on PLS and CC Pin, Relative to VSS Voltage Range on PIO Pin, Relative to VSS Voltage Range on Any Other Pin, Relative to VSS Continuous Internal Sense Resistor Current Pulsed Internal Sense Resistor Current Operating Temperature Range Storage Temperature Range Soldering Temperature -0.3V to +18V -0.3V to +12V -0.3V to +6V ±2.
PAGE 3
DS2762 High-Precision Li+ Battery Monitor With Alerts ELECTRICAL CHARACTERISTICS: PROTECTION CIRCUITRY (2.5V £ VDD £ 5.5V, TA = 0°C to +50°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX 4.325 4.350 4.375 4.250 4.275 4.300 UNITS Overvoltage Detect VOV (Notes 1, 2) Charge Enable VCE (Note 1) 4.10 4.15 4.20 V Undervoltage Detect VUV (Note 1) 2.5 2.6 2.7 V Overcurrent Detect IOC (Note 3) 1.8 1.9 2.0 A Overcurrent Detect VOC (Note 1, 4) 45 47.
PAGE 4
DS2762 High-Precision Li+ Battery Monitor With Alerts ELECTRICAL CHARACTERISTICS: TEMPERATURE, VOLTAGE, CURRENT (2.5V £ VDD £ 5.5V, TA = -20°C to +50°C.) PARAMETER SYMBOL Temperature Resolution TLSB Temperature Full-Scale Magnitude TFS Temperature Error TERR Voltage Resolution VLSB Voltage Full-Scale Magnitude VFS Voltage Gain Error VGERR Current Resolution ILSB Current Full-Scale Magnitude IFS MAX °C ±3 (Note 6) 4.
PAGE 5
DS2762 High-Precision Li+ Battery Monitor With Alerts ELECTRICAL CHARACTERISTICS: 1-WIRE INTERFACE (2.5V £ VDD £ 5.5V, TA = -20°C to +70°C.
PAGE 6
DS2762 High-Precision Li+ Battery Monitor With Alerts PIN DESCRIPTION PIN TSSOP FLIP CHIP SYMBOL FUNCTION 1 C1 CC Charge Protection Control Output. Controls an external P-channel high-side charge protection FET. 2 B1 PLS Battery Pack Positive Terminal Input. The DS2762 monitors the pack plus terminal through PLS to detect overcurrent and overload conditions, as well as the presence of a charge source. Additionally, a charge path to recover a deeply depleted cell is provided from PLS to VDD.
PAGE 7
DS2762 High-Precision Li+ Battery Monitor With Alerts Figure 1. Block Diagram 1-Wire INTERFACE AND ADDRESS DQ REGISTERS AND USER MEMORY DS2762 VOLTAGE REFERENCE THERMAL SENSE LOCKABLE EEPROM SRAM TEMPERATURE VOLTAGE VIN IS1 IS2 MUX + ADC CURRENT ACCUM.
PAGE 8
DS2762 High-Precision Li+ Battery Monitor With Alerts Figure 2. Application Example 102 x 2 BAT+ PACK+ 1kW 1kW 150W 1kW DS2762 150W 150W DATA 102 CC PLS DC SNS SNS SNS DQ IS2 VIN VDD PIO VSS VSS VSS PS IS1 PIO 104 PS 4.7kW 104 PACK- BATRSNS (NOTE 1) RSNS-INT (NOTE 2) RKS IS2 4.7kW SNS VOLTAGE SENSE DS2762 8 of 25 VSS 4.7kW NOTE 1: RSNS IS PRESENT FOR EXTERNAL SENSE RESISTOR CONFIGURATIONS ONLY. NOTE 2: RSNS-INT IS PRESENT FOR INTERNAL SENSE RESISTOR CONFIGURATIONS ONLY.
PAGE 9
DS2762 High-Precision Li+ Battery Monitor With Alerts POWER MODES The DS2762 has two power modes: active and sleep. While in active mode, the DS2762 continually measures current, voltage, and temperature to provide data to the host system and to support current accumulation and Li+ safety monitoring. In sleep mode, the DS2762 ceases these activities.
PAGE 10
DS2762 High-Precision Li+ Battery Monitor With Alerts register, and enters sleep mode. The DS2762 provides a current-limited (IRC) recovery charge path from PLS to VDD to gently charge severely depleted cells. The recovery path is enabled when 0 £ VDD < 3V (typ). Once VDD reaches 3V (typ), the DS2762 returns to normal operation, awaiting connection of a charger to turn on the charge FET and pull out of sleep mode. Overcurrent, Charge Direction.
PAGE 11
DS2762 High-Precision Li+ Battery Monitor With Alerts CURRENT MEASUREMENT In active mode, the DS2762 continually measures the current flow into and out of the battery by measuring the voltage drop across a current-sense resistor. The DS2762 is available in two configurations: 1) internal 25mW current-sense resistor and 2) external user-selectable sense resistor.
PAGE 12
DS2762 High-Precision Li+ Battery Monitor With Alerts CURRENT OFFSET COMPENSATION Current measurement and current accumulation are internally compensated for offset on a continual basis minimizing error resulting from variations in device temperature and voltage. Additionally, a constant bias can be used to alter any other sources of offset. This bias resides in EEPROM address 33h in two’s-complement format and is subtracted from each current measurement.
PAGE 13
DS2762 High-Precision Li+ Battery Monitor With Alerts PROGRAMMABLE I/O To use the PIO pin as described in this section, the IE bit (bit 2) of the Status Register must be set to 0. To use the PIO pin as an output, write the desired output value to the PIO bit in the special feature register. Writing a 0 to the PIO bit enables the PIO output driver, pulling the PIO pin to VSS. Writing a 1 to the PIO bit disables the output driver, allowing the PIO pin to be pulled high or used as an input.
PAGE 14
DS2762 High-Precision Li+ Battery Monitor With Alerts Temperature Interrupt High Threshold Address 84 S 6 2 5 4 2 2 3 2 2 2 1 2 MSb 0 2 LSb Units: 1.0°C Temperature Alarm Low Threshold Address 85 S 6 2 5 2 4 2 3 2 MSb 2 2 1 2 0 2 LSb Units: 1.0°C POWER SWITCH INPUT The DS2762 provides a power control function that uses the discharge protection FET to gate battery power to the system.
PAGE 15
DS2762 High-Precision Li+ Battery Monitor With Alerts Table 2.
PAGE 16
DS2762 High-Precision Li+ Battery Monitor With Alerts OV—Overvoltage Flag. When set to 1, this bit indicates the battery pack has experienced an overvoltage condition. This bit must be reset by the host system. UV—Undervoltage Flag. When set to 1, this bit indicates the battery pack has experienced an undervoltage condition. This bit must be reset by the host system. COC—Charge Overcurrent Flag. When set to 1, this bit indicates the battery pack has experienced a chargedirection overcurrent condition.
PAGE 17
DS2762 High-Precision Li+ Battery Monitor With Alerts EEPROM REGISTER The format of the EEPROM register is shown in Figure 12. The function of each bit is described in detail in the following paragraphs. Figure 12. EEPROM Register Format ADDRESS 07 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 EEC LOCK X X X X BL1 BL0 EEC—EEPROM Copy Flag. A 1 in this read-only bit indicates that a copy data command is in progress. While this bit is high, writes to EEPROM addresses are ignored.
PAGE 18
DS2762 High-Precision Li+ Battery Monitor With Alerts 1-Wire BUS SYSTEM The 1-Wire bus is a system that has a single bus master and one or more slaves. A multidrop bus is a 1-Wire bus with multiple slaves. A single-drop bus has only one slave device. In all instances, the DS2762 is a slave device. The bus master is typically a microprocessor in the host system. The discussion of this bus system consists of four topics: 64-bit net address, hardware configuration, transaction sequence, and 1-Wire signaling.
PAGE 19
DS2762 High-Precision Li+ Battery Monitor With Alerts HARDWARE CONFIGURATION Because the 1-Wire bus has only a single line, it is important that each device on the bus be able to drive it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must connect to the bus with open-drain or tri-state output drivers. The DS2762 used an open-drain output driver as part of the bidirectional interface circuitry shown in Figure 16.
PAGE 20
DS2762 High-Precision Li+ Battery Monitor With Alerts NET ADDRESS COMMANDS Once the bus master has detected the presence of one or more slaves, it can issue one of the net address commands described in the following paragraphs. The name of each ROM command is followed by the 8-bit opcode for that command in square brackets. Figure 17 presents a transaction flowchart of the net address commands. Read Net Address [33h or 39h]. This command allows the bus master to read the DS2762’s 1-Wire net address.
PAGE 21
DS2762 High-Precision Li+ Battery Monitor With Alerts Write Data [6Ch, XX]. This command writes data to the DS2762 starting at memory address XX. The LSb of the data to be stored at address XX can be written immediately after the MSb of address has been entered. Because the address is automatically incremented after the MSb of each byte is written, the LSb to be stored at address XX + 1 can be written immediately after the MSb to be stored at address XX.
PAGE 22
DS2762 High-Precision Li+ Battery Monitor With Alerts Figure 17.
PAGE 23
DS2762 High-Precision Li+ Battery Monitor With Alerts I/O SIGNALING The 1-Wire bus requires strict signaling protocols to ensure data integrity. The four protocols used by the DS2762 are as follows: the initialization sequence (reset pulse followed by presence pulse), write 0, write 1, and read data. The bus master initiates all these types of signaling except the presence pulse. The initialization sequence required to begin any communication with the DS2762 is shown in Figure 18.
PAGE 24
DS2762 High-Precision Li+ Battery Monitor With Alerts Figure 19.
PAGE 25
DS2762 High-Precision Li+ Battery Monitor With Alerts SELECTOR GUIDE PART DS2762AE+ DS2762BE+ DS2762AE+T&R DS2762BE+T&R DS2762AE+025 DS2762BE+025 DS2762AE+025/T&R DS2762BE+025/T&R DS2762AX-025/T&R DS2762BX-025/T&R DS2762AX/T&R DS2762BX/T&R DS2762AE DS2762BE DS2762AE/T&R DS2762BE/T&R DS2762AE-025 DS2762BE-025 DS2762AE-025/T&R DS2762BE-025/T&R MARKING DS2762A DS2762B DS2762A DS2762B 2762A25 2762B25 2762A25 2762B25 DS2762AR DS2762BR DS2762A DS2762B DS2762A DS2762B DS2762A DS2762B 2762A25 2762B25 2762A25 2762