鉃?/div>
Logic-level controlled low-power
mode (< 5碌A(chǔ) standby current)
General Description
The bq2004E and bq2004H Fast
Charge ICs provide comprehensive
fast charge control functions together
with high-speed switching power con-
trol circuitry on a monolithic CMOS
device.
Integration of closed-loop current
control circuitry allows the bq2004
to be the basis of a cost-effective so-
lution for stand-alone and system-
integrated chargers for batteries of
one or more cells.
Switch-activated discharge-before-
charge allows bq2004E/H-based charg-
ers to support battery conditioning
and capacity determination.
High-efficiency power conversion is
accomplished using the bq2004E/H as
a hysteretic PWM controller for
switch-mode regulation of the charg-
ing current. The bq2004E/H may al-
ternatively be used to gate an exter-
nally regulated charging current.
Fast charge may begin on application
of the charging supply, replacement
of the battery, or switch depression.
For safety, fast charge is inhibited
unless/until the battery tempera-
ture and voltage are within config-
ured limits.
Temperature, voltage, and time are
monitored throughout fast charge.
Fast charge is terminated by any of
the following:
n
Rate of temperature rise
(鈭員/鈭唗)
Peak voltage detection (PVD)
Negative delta voltage (-鈭哣)
Maximum voltage
Maximum temperature
Maximum time
n
n
n
n
n
After fast charge, optional top-off
and pulsed current maintenance
phases with appropriate display
mode selections are available.
T h e bq 20 04 H d i f f er s f r om th e
bq2004E only in that fast charge,
hold-off, and top-off time units have
been scaled up by a factor of two,
and the bq2004H provides different
display selections. Timing differ-
ences between the two ICs are illus-
trated in Table 1. Display differ-
ences are shown in Table 2.
Pin Connections
Pin Names
DCMD
Discharge command
Display select
Voltage termination
select
Timer mode select 1
Timer mode select 2
Temperature cutoff
Temperature sense
Battery voltage
INH
SNS
LED
1
LED
2
V
SS
V
CC
MOD
DIS
Sense resistor input
Charge status output 1
Charge status output 2
System ground
5.0V
鹵
10% power
Charge current control
Discharge control
output
Charge inhibit input
DSEL
VSEL
TM
1
TM
2
TCO
TS
BAT
DCMD
DSEL
VSEL
TM1
TM2
TCO
TS
BAT
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
INH
DIS
MOD
VCC
VSS
LED2
LED1
SNS
16-Pin Narrow DIP
or Narrow SOIC
PN2004E01.eps
6/99 E
1