Datasheet

TPS54120
SBVS180C –JANUARY 2012–REVISED JUNE 2012 www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
At T
J
= –40°C to +125°C, V
(PVIN)
= V
(VIN)
= 12 V, V
(LDOIN)
= DC-DC_OUT
(1)
= 4.1 V, V
(OUT)
= 3.3 V, I
(OUT)
= 10 mA,
V
(EN)
= floating, C
(OUT)
= 100 μF, unless otherwise noted.
TPS54120
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
LDO
V
(LDOIN)
LDO input voltage range 2.2 6.5 V
V
(FB)
FB pin voltage 0.8 V
V
(OUT)
OUT pin voltage range V
(FB)
6.0 V
I
(OUT)
≤ 1 A, V
(OUT_nom)
+ 0.5 V ≤ V
(LDOIN)
≤ 6.5 V,
OUT pin voltage accuracy –3.0% ±0.3% 3.0%
V
(FB)
≤ V
(OUT)
< 6.0 V
ΔV
O(ΔIL)
Load regulation 100 mA ≤ I
(OUT)
≤ 1 A 5 µV/mA
I
(OUT)
= 100 mA, V
(OUT_nom)
+ 0.5 V ≤ V
(LDOIN)
,
ΔV
O(ΔVI)
Line regulation 100 µV/V
4.5 V ≤ V
(VIN)
≤ 17 V
I
(OUT)
≤ 1 A, 2.5 V ≤ V
(LDOIN)
≤ 6.5 V,
V
DO
LDO dropout voltage 500 mV
V
(FB)
= GND
I
LIM
Output current limit V
(OUT)
= 0.85 × V
(OUT_nom)
1.1 1.4 2 A
I
(GND)
GND pin current I
(OUT)
≤ 1 A 350 µA
I
L(sd_LDO)
Shutdown current (I
(GND)
) V
(EN)
< 0.3 V 2 µA
I
(FB)
FB pin current 1.0 µA
I
(LDOEN)
LDOEN pin input current V
(EN)
= V
(LDOIN)
20 nA
LDOEN pin low-level input voltage
V
IL(LDOEN)
0.4 V
(disable)
LDOEN pin high-level input voltage
V
IH(LDOEN)
1.4 V
(enable)
DC-DC TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Switching frequency range (RT mode set
200 1200 kHz
point and PLL mode)
Minimum switching frequency R
(RT)
= 240 kΩ (1%) 160 200 240 kHz
Switching frequency R
(RT)
= 100 kΩ (1%) 400 480 560 kHz
Maximum switching frequency R
(RT)
= 40.2 kΩ (1%) 1080 1200 1320 kHz
RT/CLK high threshold 2 V
RT/CLK low threshold 0.8 V
Minimum pulse width 20 ns
RT/CLK falling edge to PH rising edge
Measure at 500 kHz with RT resistor in series 62 ns
delay
PH PIN
minimum on time Measured at 90% of PH, T
A
= 25°C, I
PH
= 2 A 97 ns
minimum off time BOOT – PH > 3 V 0 ns
THERMAL SHUTDOWN
T
SD
Thermal shutdown temperature Shutdown, temperature increasing +160 °C
Reset, temperature decreasing +140 °C
NOISE
BW = 100 Hz to 100 kHz, C
(OUT)
= 100 µF,
9 µV
RMS
C
(NR)
= 0.01 µF, C
(FB)
= 0.01 µF, I
(OUT)
= 100 mA
BW = 100 Hz to 1 MHz, C
(OUT)
= 100 µF,
17 µV
RMS
C
(NR)
= 0.01 µF, C
(FB)
= 0.01 µF, I
(OUT)
= 100 mA
V
n
Output noise voltage
BW = 10 Hz to 1 MHz, C
(OUT)
= 100 µF,
21 µV
RMS
C
(NR)
= 0.01 µF, C
(FB)
= 0.01 µF, I
(OUT)
= 100 mA
W = 10 Hz to 10 MHz, C
(OUT)
= 100 µF,
38 µV
RMS
C
(NR)
= 0.01 µF, C
(FB)
= 0.01 µF, I
(OUT)
= 100 mA
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