TI-BQ2014：精确监控可充电电池电量与自放电的气体 gauge IC
需积分: 9 197 浏览量
更新于2024-06-30
5
收藏 843KB PDF 举报
TI-BQ2014是一款专为可充电电池包设计的精密气体传感器集成电路，其核心功能在于提供可靠且可重复的电池剩余电量测量。该IC的特点包括：
1. 保守与可重复的电量测量：BQ2014通过监控电池正负极之间的电压降，使用内置的敏感电阻来准确评估电池的充放电状态，确保数据的一致性和可靠性。
2. 集成外设控制：它具备一个输出接口，可以驱动外部的充电控制器，如BQ2004 FastCharge IC，实现对电池充电过程的精确控制。
3. 低功耗设计：典型待机电流仅为120微安，对于能源管理至关重要的应用来说，这极大地延长了系统的电池寿命。
4. 多种通信方式：用户可以选择通过单线串行通信端口或者直接驱动LED显示剩余电量、电压、温度等关键信息，方便实时监控和远程读取。
5. 补偿功能：针对镍氢(NiMH)和镍镉(NiCd)电池的自放电特性，内部集成的定时器和温度传感器能够进行自动补偿，确保测量结果不受时间或温度变化的影响。
6. 用户可配置：允许用户设置电池放电阈值，根据具体应用需求定制电池保护策略。
7. 紧凑封装：采用16引脚窄型SOIC封装，便于在小型电池包设计中轻松集成。
BQ2014是一款高度集成、功能强大的电池管理系统，它不仅提供了精确的电池状态监测，还优化了系统的能耗管理和用户体验。无论是在便携设备还是工业级应用中，都能有效提升电池管理的效率和可靠性。
Gas Gauge Operation
The operational overview diagram in Figure 2 illustrates
the operation of the bq2014. The bq2014 accumulates a
measure of charge and discharge currents, as well as an
estimation of self-discharge. Charge and discharge cur-
rents are temperature and rate compensated, whereas
self-discharge is only temperature compensated.
The main counter, Nominal Available Charge (NAC),
represents the available battery capacity at any given
time. Battery charging increments the NAC register,
while battery discharging and self-discharge decrement
the NAC register and increment the DCR (Discharge
Count Register).
The Discharge Count Register (DCR) is used to update
the Last Measured Discharge (LMD) register only if a
complete battery discharge from full to empty occurs
without any partial battery charges. Therefore, the
bq2014 adapts its capacity determination based on the
actual conditions of discharge.
The battery's initial capacity is equal to the Pro-
grammed Full Count (PFC) shown in Table 2. Until
LMD is updated, NAC counts up to but not beyond this
threshold during subsequent charges. This approach al-
lows the gas gauge to be charger-independent and com-
patible with any type of charge regime.
Many actions in the bq2014 are triggered by detection of
a “valid charge.” NAC is stored in an asynchronous, 2-
byte counter; the lower byte is NACL and the upper byte
is NACH. A valid charge has occurred anytime the
charge lasts long enough to cause an increment in
NACH. Small increments of charging are not consid
-
ered “valid” if they result in counts in NACL but do not
generate a roll-over (carry) that increments NACH.
NACL is reset anytime the counter direction changes
from down to up, so the number of counts required to
cause a roll-over and a valid charge is always 256. The
counter may be incrementing by 2, 4, 8, or more counts
per increment, however, depending on the scaling fac-
tors selected. Therefore, a valid charge may be consti-
tuted by a smaller number of counter increments.
1. Last Measured Discharge (LMD) or
learned battery capacity:
LMD is the last measured discharge capacity of the
battery. On initialization (application of V
CC
or bat-
tery replacement), LMD = PFC. During subsequent
discharges, the LMD is updated with the latest
measured capacity in the Discharge Count Register
(DCR) representing a discharge from full to below
EDV1. A qualified discharge is necessary for a ca-
pacity transfer from the DCR to the LMD register.
The LMD also serves as the 100% reference thresh-
old used by the relative display mode.
2. Programmed Full Count (PFC) or initial
battery capacity:
The initial LMD and gas gauge rate values are pro-
grammed by using PROG
1
—PROG
4
. The bq2014 is
configured for a given application by selecting a
PFC value from Table 2. The correct PFC may be
5
bq2014
FG201002.eps
Rate and
Temperature
Compensation
Temperature
Compensation
Charge
Current
Discharge
Current
Self-Discharge
Timer
Temperature
Translation
Nominal
Available
Charge
(NAC)
Last
Measured
Discharged
(LMD)
Discharge
Count
Register
(DCR)
<
Qualified
Transfer
+
Rate and
Temperature
Compensation
Rate and
Temperature
Compensation
Temperature Step,
Other Data
+
--
+
Inputs
Main Counters
and Capacity
Reference (LMD)
Outputs
Serial
Port
Chip-Controlled
Available Charge
LED Display
Figure 2. Operational Overview
剩余25页未读，继续阅读
点击了解资源详情
点击了解资源详情
点击了解资源详情
2022-10-29 上传
2022-11-12 上传
2022-10-29 上传
2022-12-10 上传
2022-12-06 上传
2023-04-22 上传
