TPS40070
TPS40071
www.ti.com . SLUS582J – DECEMBER 2003 – REVISED APRIL 2009 HIGH-EFFICIENCY MIDRANGE INPUT SYNCHRONOUS
BUCK CONTROLLER WITH VOLTAGE FEED-FORWARD
FEATURES 1 Operation Over 4.5-V to 28-V Input Range Programmable Fixed-Frequency up to 1-MHz
Voltage-Mode Controller Predictive Gate Driveв„ў With Anti-Cross
Conduction Circuitry 10 V Output voltage 7 8 4.0 4.3 TA = TJ = 25°C 0.698 0.700 0.704 0°C ≤ TA≤ 85°C 0.690 0.700 0.707 40°C ≤ TA≤ 85°C 0.690 0.700 0.715 VDD = 4.5 V, IOUT = 25 mA 9 V ERROR AMPLIFIER
VFB Feedback regulation voltage total variation
Soft-start offset from VSS (2) VSS Offset from VSS to error amplifier (2) 1 GBW Gain bandwidth AVOL Open loop gain 50 ISRC Output source current 2.5 4.5 ISINK Output sink current 2.5 6 IBIAS Input bias current (1)
(2) 5 VFB = 0.7 V V –250 10 MHz
dB
mA
0 nA For zero output voltage only. Does not assure lack of activity on HDRV or LDRV.
Ensured by design. Not production tested. Copyright © 2003–2009, Texas Instruments Incorporated Product Folder Link(s): TPS40070 TPS40071 Submit Documentation Feedback 3 TPS40070
TPS40071
SLUS582J – DECEMBER 2003 – REVISED APRIL 2009 . www.ti.com ELECTRICAL CHARACTERISTICS (continued)
TA = –40°C to 85°C, VIN = 12 Vdc, RT = 90.9 kΩ, IKFF = 300 A, fSW = 500 kHz, all parameters at zero power dissipation (unless
otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 80 105 125 µA –75 –50 –30 mV 135 225 ns SHORT CIRCUIT CURRENT PROTECTION
IILIM Current sink into current limit VILIM(ofst) Current limit offset voltage VILIM = 11.5 V, (VSW -VILIM) VDD = 12 V tHSC Minimum HDRV pulse width During short circuit Propagation delay to output (3) 50 ns tBLANK Blanking time (3) 50 ns tOFF Off time during a fault (SS cycle times) 7 cycles VSW Switching level to end precondition (3) tPC Precondition time (3) VILIM Current limit precondition voltage threshold (3) (VDD -VSW) 2 V
100 6.8 ns
V OUTPUT DRIVERS
tHFALL High-side driver fall time (3) tHRISE High-side driver rise time (3) tHFALL High-side driver fall time (3) tHRISE High-side driver rise time (3) tLFALL Low-side driver fall time (3) …
