Datasheet
ELECTRICAL CHARACTERISTICS
TPS55383 , , TPS55386
SLUS818 – SEPTEMBER 2008 .........................................................................................................................................................................................
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– 40 ° C ≤ T
J
≤ +125 ° C, V
PVDD1
= V
PVDD2
= 12 V, unless otherwise noted.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
INPUT SUPPLY (PVDD)
V
PVDD1
Input voltage range 4.5 28 V
V
PVDD2
IDD
SDN
Shutdown V
EN1
= V
EN2
= V
PVDD2
70 150 µ A
IDD
Q
Quiescent, non-switching V
FB
= 0.9 V, Outputs OFF 1.8 3.0
mA
SW node unloaded; Measured as BP sink
IDD
SW
Quiescent, while-switching 5
current
V
UVLO
Minimum turn-on voltage PVDD2 only 3.8 4.1 4.4 V
V
UVLO(hys)
Hysteresis 400 600 mV
C
BP
= 10 µ F, EN1 and EN2 go low
t
START
(1) (2)
Time from startup to softstart begin 2 ms
simultaneously
ENABLE ( EN)
V
EN1
, V
EN2
Enable threshold 0.9 1.2 1.5 V
Enable threshold hysteresis
(1)
50 mV
I
EN1
. I
EN2
Enable pull-up current V
EN1
= V
EN2
= 0 V 6 12 µ A
t
EN
(1)
Time from enable to soft-start begin Other EN pin = GND 10 µ s
BP REGULATOR (BP)
BP Regulator voltage 8 V < P
VDD2
< 28 V 5 5.25 5.6 V
P
VDD2
= 4.5 V; switching, no external load on
BP
LDO
Dropout voltage 400 550 mV
BP
I
BP
(1)
Regulator external load 2
mA
I
BPS
Regulator short circuit 4.5 V < P
VDD2
< 28 V 10 20 30
OSCILLATOR
TPS55383 255 310 375
f
SW
Switching frequency kHz
TPS55386 510 630 750
t
DEAD
(1)
Clock dead time 140 ns
ERROR AMPLIFIER (EA) and VOLTAGE REFERENCE (REF)
0 ° C < T
J
< +85 ° C 786 800 812
V
FB1,
V
FB2
Feedback input voltage mV
– 40 ° C < T
J
< +125 ° C 784 812
I
FB1,
I
FB2
Feedback input bias current 3 50 nA
g
M
1, g
M
2
(1)
Error Amplifier transconductance 220 315 420 µ S
f
p1
, f
p2
(1)
Error Amplifier dominant pole frequency 5 6 kHz
I
SINK(COMP1)
,
Error Amplifier sink current capability V
FB1
= V
FB2
= 0.9V, V
COMP
= 2 V 15 30 40 µ A
I
SINK(COMP2)
I
SRC(COMP1)
,
Error Amplifier source current capability V
FB1
= V
FB2
= 0.7V, V
COMP
= 0 V 15 30 40 µ A
I
SRC(COMP2)
SOFT START (SS)
T
SS1
, T
SS2
Soft start time 1.5 2.1 2.7 ms
(1) Ensured by design. Not production tested.
(2) When both outputs are started simultaneously, a 20-mA current source charges the BP capacitor. Faster times are possible with a lower
BP capacitor value. More information can be found in the Input UVLO and Startup section.
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