Datasheet

The first end-of-discharge warning flag (EDV1)
warns the user that the battery is almost empty. The
first segment pin, SEG
1
, is modulated at a 4Hz rate if
the display is enabled once EDV1 is asserted, which
should warn the user that loss of battery power is immi
-
nent. The EDV1 flag is latched until a valid charge has
been detected. The EDV1 threshold is externally con
-
trolled via the VTS register (see Voltage Threshold Reg
-
ister).
The EDV1 values are:
Where EDV1 is:
0 Valid charge action detected, V
SB
≥
V
TS
1V
SB
<V
TS
providing that the discharge rate
is<2C
The final end-of-discharge warning flag (EDVF) flag
is used to warn that battery power is at a failure condi-
tion. All segment drivers are turned off. The EDVF flag
is latched until a valid charge has been detected. The
EDVF threshold is set 25mV below the EDV1 threshold.
The EDVF values are:
Where EDVF is:
0 Valid charge action detected, V
SB
≥
(V
TS
- 25mV)
1V
SB
< (V
TS
-25mV) providing the discharge
rate is < 2C
Temperature Register (TMP)
The TMP register (address=02h) contains the battery
temperature.
The bq2050H contains an internal temperature sensor.
The temperature is used to set charge and discharge ef
-
ficiency factors as well as to adjust the self-discharge co
-
efficient. The temperature register contents may be
translated as shown in Table 9.
The bq2050H calculates the gas gauge bits, GG3-GG0 as a
function of CACT and LMD. The results of the calculation
give available capacity in
1
16
increments from 0 to
15
16
.
Nominal Available Capacity Registers
(NACH/NACL)
The NACH high-byte register (address=03h) and the
NACL low-byte register (address=17h) are the main gas
gauging registers for the bq2050H. The NAC registers are
incremented during charge actions and decremented dur
-
ing discharge and self-discharge actions. NACH and
NACL are set to 0 during a bq2050H reset.
Writing to the NAC registers affects the available charge
counts and, therefore, affects the bq2050H gas gauge opera
-
tion. Do not write the NAC registers to a value greater than
LMD.
Battery Identification Register (BATID)
The BATID register (address=04h) is available for use
by the system to determine the type of battery pack.
The BATID contents are retained as long as V
RBI
is
greater than 2V. The contents of BATID have no effect
on the operation of the bq2050H. There is no default
setting for this register.
14
bq2050H
TMP3 TMP2 TMP1 TMP0 Temperature
0000 T < -30°C
0001-30°C < T < -20°C
0010-20°C < T < -10°C
0011-10°C < T < 0°C
01000°C < T < 10°C
010110°C < T < 20°C
011020°C < T < 30°C
011130°C < T < 40°C
100040°C < T < 50°C
100150°C < T < 60°C
101060°C < T < 70°C
101170°C < T < 80°C
1100 T > 80°C
Table 9. Temperature Register
TMP Gas Gauge Bits
76 5 4 32 1 0
- - - - GG3 GG2 GG1 GG0
FLGS1 Bits
7654 3 2 1 0
- - - - - - EDV1 -
FLGS1 Bits
7654 3 2 1 0
---- - - -EDVF
TMP Temperature Bits
765 43210
TMP3 TMP2 TMP1 TMP0 - - - -