Datasheet

bq28400
www.ti.com SLUSA61A –OCTOBER 2010–REVISED DECEMBER 2010
ELECTRICAL CHARACTERISTICS (continued)
Typical values stated where T
A
= 25ºC and V
BAT
= V
PACK
= 7.2 V, Min/Max values stated where T
A
= –20ºC to 85ºC and V
BAT
= V
PACK
= 3.8 V to 18.75 V over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITION
(1)
MIN TYP MAX UNIT
Pre-Charge/ZVCHG FET Drive
V
O(PreCHGON)
= V
(PACK)
V
(PreCHGON)
–V
(ZVCHG)
, pre-charge R
GS
= 1 MΩ, V
PACK
= 10 V 9 9.5 10 V
FET on
(8)
Output voltage, V
BAT
–
V
(PreCHGOFF)
R
GS
= 1 MΩ, T
A
= –20°C to 110°C V
pre-charge FET off
(8)
0.5
C
L
= 4700 pF, V
ZVCHG
: 10% to
t
r
Rise time 80 200 µs
R
G
= 5.1 kΩ 90%
C
L
= 4700 pF, V
ZVCHG:
90% to
t
f
Fall time 1.7 ms
R
G
= 5.1 kΩ 10%
SMBus
SMBus operating
f
SMB
Slave mode, SMBC 50% duty cycle 10 100 kHz
frequency
SMBus master clock
f
MAS
Master mode, no clock low slave extend 51.2 kHz
frequency
t
BUF
Bus free time between start and stop 4.7 µs
t
HD:STA
Hold time after (repeated) start 4 µs
t
SU:STA
Repeated start setup time 4.7 µs
t
SU:STO
Stop setup time 4 µs
Receive mode 0
t
HD:DAT
Data hold time ns
Transmit mode 300
t
SU:DAT
Data setup time 250 ns
t
TIMEOUT
Error signal/detect See
(9)
25 35 ms
t
LOW
Clock low period 4.7 µs
t
HIGH
Clock high period See
(10)
4 50 µs
Cumulative clock low
t
LOW:SEXT
See
(11)
25 ms
slave extend time
Cumulative clock low
t
LOW:MEXT
See
(12)
10 ms
master extend time
t
f
Clock/data fall time See
(13)
300 ns
t
r
Clock/data rise time See
(14)
1000 ns
(8) For a V
BAT
or V
PACK
input range of 3.8 V to 18.75 V, MIN V
O(FETON)
voltage is 9 V or V
(BAT)
– 1 V, whichever is less.
(9) The bq28400 times out when any clock low exceeds t
TIMEOUT
.
(10) t
HIGH:MAX
is the minimum bus idle time. SMBC = SMBD = 1 for t > 50 µs causes reset of any transaction involving bq28400 that is in
progress.
(11) t
LOW:SEXT
is the cumulative time a slave device is allowed to extend the clock cycles in one message from initial start to the stop.
(12) t
LOW:MEXT
is the cumulative time a master device is allowed to extend the clock cycles in one message from initial start to the stop.
(13) Rise time t
r
= V
ILMAX
– 0.15) to (V
IHMIN
+ 0.15).
(14) Fall time t
f
= 0.9V
DD
to (V
ILMAX
– 0.15).
Copyright © 2010, Texas Instruments Incorporated 9
Product Folder Link(s): bq28400