TPS40075 www.ti.com SLUS676A – MAY 2006 – REVISED SEPTEMBER 2007 MIDRANGE INPUT SYNCHRONOUS BUCK CONTROLLER
WITH VOLTAGE FEED-FORWARD
FEATURES 1 Operation Over 4.5-V to 28-V Input Range Fixed-Frequency Voltage-Mode Controller Integrated Unity Gain Amplifier for Remote
Output Sensing Predictive Gate Driveв„ў Generation II for
Improved Efficiency 10 V Output voltage 7 8 4.0 4.3 TA = TJ = 25°C 0.698 0.700 0.704 0°C ≤ TA = TJ ≤ 85°C 0.690 0.700 0.707 -40°C ≤ TA = TJ ≤ 85°C 0.690 0.700 0.715 VVDD = 4.5 V, IOUT = 25 mA 9 V ERROR AMPLIFIER
VFB Feedback regulation voltage total variation VSS(offset) Soft-start offset from VSS (1) Offset from VSS to error amplifier (1) 1 GBWP Gain bandwidth AVOL Open loop gain 50 5 ISRC Output source current 2.5 4.5 ISINK Output sink current 2.5 6 IBIAS Input bias current VFB = 0.7 V V 10 MHz
dB –250 mA
0 nA SHORT CIRCUIT CURRENT PROTECTION
IILIM Current sink into ILIM pin VILIM(ofst) Current limit offset voltage VILIM = 11.5 V, (VSW -VILIM) VVDD = 12 V tHSC Minimum HDRV pulse width During short circuit tBLANK (1)
4 115 135 150 µA –50 –30 –10 mV 135 225 ns Propagation delay to output (1) 50 ns (1) 50 ns Blanking time Ensured by design. Not production tested.
Submit Documentation Feedback Copyright © 2006–2007, Texas Instruments Incorporated Product Folder Link(s) :TPS40075 TPS40075 www.ti.com SLUS676A – MAY 2006 – REVISED SEPTEMBER 2007 ELECTRICAL CHARACTERISTICS (continued)
TA = –40°C to 85°C, VIN = 12 Vdc, RT = 90.9 kΩ, IKFF = 300 µA, fSW = 500 kHz, all parameters at zero power dissipation
(unless otherwise noted)
PARAMETER TEST CONDITIONS tOFF Off time during a fault (SS cycle times) VSW Switching level to end precondition (1) tPC Precondition time VILIM(pre) Current limit precondition voltage threshold (2) MIN TYP MAX 7
(VVDD -VSW) 2 (2) UNIT
cycles
V 100
6.8 ns
V OUTPUT DRIVERS
tHFALL High-side driver fall time (2) tHRISE High-side driver rise time (2) tHFALL High-side driver fall time (2)
(2) tHRISE High-side driver rise time tLFALL Low-side driver fall time (2) tLRISE Low-side driver rise time (2) tLFALL Low-side driver fall time (2) tLRISE Low-side driver rise time (2) VOH High-level output voltage, HDRV VOL Low-level output voltage, HDRV VOH High-level output voltage, LDRV VOL Low-level output voltage, LDRV 36 CHDRV = 2200 pF, (HDRV -SW) ns 48
72 CHDRV = 2200 pF, (HDRV -SW)
VVDD= 4.5 V ns 96 …
