Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - battery management Charge indicator NiCd, NiMH SOIC 16 N Surface-mount

Features

➤

Conservative and repeatable

measurement of available charge

in rechargeable batteries

➤

Designed for battery pack inte

gration

120µA typical standby current

Small size enables imple-

mentations in as little as

square inch of PCB

➤

Integrate within a system or as a

stand-alone device

Display capacity via single-

wire serial communication

port or direct drive of LEDs

➤ Measurements compensated for

current and temperature

➤ Self-discharge compensation us-

ing internal temperature sensor

➤ Accurate measurements across a

wide range of current (> 500:1)

➤ 16-pin narrow SOIC

General Description

The bq2010 Gas Gauge IC is intended

for battery-pack or in-system installa

tion to maintain an accurate record of

a battery's available charge. The IC

monitors a voltage drop across a

sense resistor connected in series be

tween the negative battery terminal

and ground to determine charge and

discharge activity of the battery.

NiMH and NiCd battery self-dis

charge is estimated based on an inter

nal timer and temperature sensor.

Compensations for battery tempera

ture and rate of charge or discharge

are applied to the charge, discharge,

and self-discharge calculations to pro

vide available charge information

across a wide range of operating con-

ditions. Battery capacity is automati-

cally recalibrated, or “learned,” in the

course of a discharge cycle from full to

empty.

Nominal available charge may be

directly indicated using a five- or

six-segment LED display. These seg-

ments are used to indicate graphi-

cally the nominal available charge.

The bq2010 supports a simple

single-line bidirectional serial link to

an external processor (common

ground). The bq2010 outputs battery

information in response to external

commands over the serial link.

The bq2010 may operate directly

from 3 or 4 cells. With the REF out

put and an external transistor, a sim

ple, inexpensive regulator can be built

to provide V

across a greater

number of cells.

Internal registers include available

charge, temperature, capacity, battery

ID, battery status, and programming

pin settings. To support subassembly

testing, the outputs may also be con

trolled. The external processor may

also overwrite some of the bq2010

gas gauge data registers.

LCOM LED common output

SEG

/PROG

LED segment 1/

program 1 input

SEG

/PROG

LED segment 2/

program 2 input

SEG

/PROG

LED segment 3/

program 3 input

SEG

/PROG

LED segment 4/

program 4 input

SEG

/PROG

LED segment 5/

program 5 input

SEG

/PROG

LED segment 6/

program 6 input

PN201001.eps

16-Pin Narrow SOIC

REF

EMPTY

DISP

LCOM

SEG

/PROG

SEG

/PROG

SEG

/PROG

SEG

/PROG

SEG

/PROG

SEG

/PROG

REF Voltage reference output

NC No connect

DQ Serial communications

input/output

EMPTY Empty battery indicator

output

SB Battery sense input

DISP

Display control input

SR Sense resistor input

3.0–6.5V

System ground

bq2010

Pin Connections

Pin Names

4/95 D

Gas Gauge IC

Summary of content (25 pages)

PAGE 1
bq2010 Gas Gauge IC Features General Description ➤ Conservative and repeatable measurement of available charge in rechargeable batteries The bq2010 Gas Gauge IC is intended for battery-pack or in-system installation to maintain an accurate record of a battery's available charge. The IC monitors a voltage drop across a sense resistor connected in series between the negative battery terminal and ground to determine charge and discharge activity of the battery.
PAGE 2
bq2010 SR Pin Descriptions LCOM The voltage drop (VSR) across the sense resistor RS is monitored and integrated over time to interpret charge and discharge activity. The SR input is tied to the high side of the sense resistor. VSR < VSS indicates discharge, and VSR > VSS indicates charge. The effective voltage drop, VSRO, as seen by the bq2010 is VSR + VOS (see Table 5). LED common output Open-drain output switches VCC to source current for the LEDs.
PAGE 3
bq2010 Figure 1 shows a typical battery pack application of the bq2010 using the LED display capability as a chargestate indicator. The bq2010 can be configured to display capacity in either a relative or an absolute display mode. The relative display mode uses the last measured discharge capacity of the battery as the battery “full” reference. The absolute display mode uses the programmed full count (PFC) as the full reference, forcing each segment of the display to represent a fixed amount of charge.
PAGE 4
bq2010 charge display translation. The temperature range is available over the serial port in 10°C increments as shown below: Voltage Thresholds In conjunction with monitoring VSR for charge/discharge currents, the bq2010 monitors the single-cell battery potential through the SB pin.
PAGE 5
bq2010 1. Gas Gauge Operation The operational overview diagram in Figure 2 illustrates the operation of the bq2010. The bq2010 accumulates a measure of charge and discharge currents, as well as an estimation of self-discharge. Charge and discharge currents are temperature and rate compensated, whereas self-discharge is only temperature compensated. LMD is the last measured discharge capacity of the battery. On initialization (application of VCC or battery replacement), LMD = PFC.
PAGE 6
bq2010 Example: Selecting a PFC Value Select: Given: PFC = 33792 counts or 211mVh PROG1 = float PROG2 = float PROG3 = float PROG4 = low PROG5 = float PROG6 = float Sense resistor = 0.
PAGE 7
bq2010 3. 4. Nominal Available Charge (NAC): Discharge Counting NAC counts up during charge to a maximum value of LMD and down during discharge and self-discharge to 0. NAC is reset to 0 on initialization (PROG6 = Z or low) and on the first valid charge following discharge to EDV1. NAC is set to PFC on initialization if PROG6 = high. To prevent overstatement of charge during periods of overcharge, NAC stops incrementing when NAC = LMD.
PAGE 8
bq2010 The compensation factors during discharge are: Digital Magnitude Filter Approximate VSR Threshold Discharge Compensation Factor Efficiency VSR > -150 mV 1.00 100% VSR < -150 mV 1.05 95% The bq2010 has a programmable digital filter to eliminate charge and discharge counting below a set threshold. The default setting is -0.30mV for V SRD and +0.38mV for VSRQ. The proper digital filter setting can be calculated using the following equation. Table 4 shows typical digital filter settings.
PAGE 9
bq2010 Table 5. bq2010 Current-Sensing Errors Symbol Parameter Typical Maximum Units ± 50 ± 150 µV Notes DISP = VCC. VOS Offset referred to VSR INL Integrated non-linearity error ±2 ±4 % Add 0.1% per °C above or below 25°C and 1% per volt above or below 4.25V. INR Integrated nonrepeatability error ±1 ±2 % Measurement repeatability given similar operating conditions. the bq2010 should be pulled up by the host system or may be left floating if the serial interface is not used.
PAGE 10
bq2010 Table 6. bq2010 Command and Status Registers Control Field Register Name Symbol Loc.
PAGE 11
bq2010 tected after the EDV1 flag is asserted. BRP = 1 signifies that the device has been reset. The W/R values are: CMDR Bits The BRP values are: 7 6 5 4 3 2 1 0 W/R - - - - - - - FLGS1 Bits Where W/R is: 0 The bq2010 outputs the requested register contents specified by the address portion of CMDR. 1 The lower seven-bit field of CMDR contains the address portion of the register to be accessed. Attempts to write to invalid addresses are ignored.
PAGE 12
bq2010 The EDVF values are: The valid discharge flag (VDQ) is asserted when the bq2010 is discharged from NAC=LMD. The flag remains set until either LMD is updated or one of three actions that can clear VDQ occurs: n n n FLGS1 Bits The self-discharge count register (SDCR) has exceeded the maximum acceptable value (4096 counts) for an LMD update. 7 6 5 4 3 2 1 0 - - - - - - - EDVF Where EDVF is: A valid charge action sustained at VSRO > VSRQ for at least 256 NAC counts.
PAGE 13
bq2010 The bq2010 calculates the available charge as a function of NAC, temperature, and a full reference, either LMD or PFC. The results of the calculation are available via the display port or the gas gauge field of the TMPGG register. The register is used to give available capacity in 1 16 increments from 0 to 15 16. 7 - 6 - TMPGG Gas Gauge Bits 5 4 3 2 GG3 GG2 1 GG1 of the battery from full to empty. In this way the bq2010 updates the capacity of the battery. LMD is set to PFC during a bq2010 reset.
PAGE 14
bq2010 DR2–0 and OVLD are set based on the measurement of the voltage at the SR pin relative to VSS. The rate at which this measurement is made varies with device activity. Digital Magnitude Filter (DMF) The read-write DMF register (address = 0ah) provides the system with a means to change the default settings of the digital magnitude filter. By writing different values into this register, the limits of VSRD and VSRQ can be adjusted.
PAGE 15
bq2010 SEG1 blinks at a 4Hz rate whenever VSB has been detected to be below VEDV1 (EDV1 = 1), indicating a lowbattery condition. VSB below VEDVF (EDVF = 1) disables the display output. whenever the NAC registers are counting at a rate equivalent to |VSRO| ≥ 4mV. When pulled low, the segment outputs become active immediately. A capacitor tied to DISP allows the display to remain active for a short period of time after activation by a push-button switch.
PAGE 16
bq2010 DC Electrical Characteristics (TA = TOPR) Symbol VCC VREF Parameter Minimum Typical Maximum Unit Notes Supply voltage 3.0 4.25 6.5 V VCC excursion from < 2.0V to ≥ 3.0V initializes the unit. Reference at 25°C 5.7 6.0 6.3 V IREF = 5µA Reference at -40°C to +85°C 4.5 - 7.5 V IREF = 5µA RREF Reference input impedance 2.0 5.0 - MΩ VREF = 3V - 90 135 µA VCC = 3.0V, DQ = 0 ICC Normal operation - 120 180 µA VCC = 4.25V, DQ = 0 - 170 250 µA VCC = 6.
PAGE 17
bq2010 Serial Communication Timing Specification (TA = TOPR) Symbol Parameter Minimum Typical Maximum Unit tCYCH Cycle time, host to bq2010 3 - - ms tCYCB Cycle time, bq2010 to host 3 - 6 ms tSTRH Start hold, host to bq2010 5 - - ns tSTRB Start hold, bq2010 to host 500 - - µs tDSU Data setup - - 750 µs tDH Data hold 750 - - µs tDV Data valid 1.50 - - ms tSSU Stop setup - - 2.25 ms tSH Stop hold 700 - - µs tSV Stop valid 2.
PAGE 18
bq2010 16-Pin SOIC Narrow (SN) 16-Pin SN (SOIC Narrow) D e Dimension Minimum A 0.060 A1 0.004 B 0.013 C 0.007 D 0.385 E 0.150 e 0.045 H 0.225 L 0.015 All dimensions are in inches. B E H A C A1 .004 L 18 Maximum 0.070 0.010 0.020 0.010 0.400 0.160 0.055 0.245 0.
PAGE 19
bq2010 Data Sheet Revision History Change No. Page No.
PAGE 20
PACKAGE OPTION ADDENDUM www.ti.
PAGE 21
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device BQ2010SN-D107TR Package Package Pins Type Drawing SOIC D 16 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2500 330.0 16.4 Pack Materials-Page 1 6.5 B0 (mm) K0 (mm) P1 (mm) 10.3 2.1 8.0 W Pin1 (mm) Quadrant 16.
PAGE 22
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ2010SN-D107TR SOIC D 16 2500 367.0 367.0 38.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.