Datasheet

www.ti.com
ELECTRICAL CHARACTERISTICS
TPS40222
SLUS642A – OCTOBER 2005 – REVISED JANUARY 2006
T
J
= -40°C to 125°C, 4.5 ≤ V
AVIN
= V
PVIN
≤ 5.5 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
FEEDBACK VOLTAGE
T
J
= 25°C, No load 792 800 808
V
FB
Feedback voltage mV
-40°C ≤ T
J
≤ 125°C, No load,
788 812
4.5V ≤ V
DD
≤ 7 V
I
FB
Feedback input bias current V
FB
= 0.9 V, V
AVIN
= V
PVIN
= 5 V 30 100 nA
SOFT-START
t
SS
Soft-start time V
AVIN
= V
PVIN
= 5 V 300 550 850 µs
Gm AMPLIFIER
Gm Transconductance
(1)
10 µS
GBW Gain bandwidth product
(1)
12 MHz
OSCILLATOR
f
SW
Switching frequency V
FB
> 0.7 V 1.00 1.25 1.50 MHz
f
SWFB
Minimum foldback frequency Startup/Overcurrent, V
FB
= 0 V 75 140 kHz
Foldback frequency slope
(1)
0 V < V
FB
< 0.4 V 2200 Hz/mV
V
FFB
Frequency foldback V
FB
threshold voltage
(1)
0.4 0.6 V
OVERCURRENT DETECTION
I
CL
Overcurrent threshold V
AVIN
= V
PVIN
= 5 V 2.1 2.6 3.1 A
t
ON
Minimum on-time in overcurrent
(1)
90 200 ns
HIGH SIDE MOSFET AND DRIVER
T
J
= 25°C 250
R
DS(on)
Drain-to-source on-resistance m Ω
-40°C ≤ T
J
≤ 125°C 250 550
D
MAX
Maximum duty cycle 90% 97%
I
SWL
MOSFET SW leakage current V
PVIN
= 10 V -10 -30 µA
I
BOOST
Boost current I
SW
= 100 mA, V
AVIN
= V
PVIN
= 5 V 0.5 1.0 mA
Boost diode voltage drop I
DIODE
≤ 5 mA 0.9 V
UNDERVOLTAGE LOCKOUT (UVLO)
V
ON
Turn-on voltage 3.6 3.8 4.0
V
V
HYST
Hysteresis voltage 0.4
I
Q
AVIN quiescent current 1.0 1.5 mA
THERMAL SHUTDOWN
Thermal shutdown voltage
(1)
150
°C
Thermal hysteresis
(1)
-10
(1) Ensured by design. Not production tested.
3