Datasheet

TPS54218
www.ti.com SLVS974B –SEPTEMBER 2009–REVISED JULY 2013
ELECTRICAL CHARACTERISTICS
T
J
= –40°C to 150°C, VIN = 2.95 to 6 V (unless otherwise noted)
DESCRIPTION CONDITIONS MIN TYP MAX UNIT
SUPPLY VOLTAGE (VIN PIN)
Operating input voltage 2.95 6 V
Internal under voltage lockout threshold No voltage hysteresis, rising and falling 2.6 2.8 V
Shutdown supply current EN = 0 V, 25°C, 2.95 V ≤ VIN ≤ 6 V 2 5 μA
Quiescent Current - I
q
VSENSE = 0.9 V, VIN = 5 V, 25°C, R
T
= 400 kΩ 350 500 μA
ENABLE AND UVLO (EN PIN)
Rising 1.16 1.25 1.37 V
Enable threshold
Falling 1.18
Enable rising threshold + 50 mV -3.2
Input current μA
Enable falling threshold – 50 mV -0.65
VOLTAGE REFERENCE (VSENSE PIN)
Voltage Reference 2.95 V ≤ VIN ≤ 6 V, –40°C <T
J
< 150°C 0.795 0.803 0.811 V
MOSFET
BOOT-PH = 5 V 30 60
High side switch resistance mΩ
BOOT-PH = 2.95 V 44 70
VIN = 5 V 30 60
Low side switch resistance mΩ
VIN = 2.95 V 44 70
ERROR AMPLIFIER
Input current 7 nA
Error amplifier transconductance (gm) –2 μA < I
(COMP)
< 2 μA, V
(COMP)
= 1 V 225 μmhos
Error amplifier transconductance (gm) during –2 μA < I
(COMP)
< 2 μA, V
(COMP)
= 1 V, 70 μmhos
slow start VSENSE = 0.4 V
Error amplifier source/sink V
(COMP)
= 1 V, 100 mV overdrive ±20 μA
COMP to Iswitch gm 13 A/V
CURRENT LIMIT
Current limit threshold Instantaneous peak current 2.9 3.6 A
THERMAL SHUTDOWN
Thermal Shutdown 175 °C
Hysteresis 15 °C
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Switching frequency range using RT mode 200 2000 kHz
Switching frequency R
T
= 400 kΩ 400 500 600 kHz
Switching frequency range using CLK mode 300 2000 kHz
Minimum CLK pulse width 75 ns
RT/CLK voltage R
(RT/CLK)
= 400kΩ 0.5 V
RT/CLK high threshold 1.6 2.2 V
RT/CLK low threshold 0.4 0.6 V
RT/CLK falling edge to PH rising edge delay Measure at 500 kHz with R
T
resistor in series 90 ns
PLL lock in time Measure at 500 kHz 14 μs
PH (PH PIN)
Minimum On time Measured at 50% points on PH, I
OUT
= 2 A 60 ns
Measured at 50% points on PH, VIN = 5 V, 110
I
OUT
= 0 A
Minimum Off time Prior to skipping off pulses, BOOT-PH = 2.95 V, 60 ns
I
OUT
= 2 A
Rise/Fall Time VIN = 5 V 1.5 V/ns
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