Datasheet LTC1922-1 (Analog Devices) - 3

LTC1922-1
ELECTRICAL CHARACTERISTICS The
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denotes the specifications which apply over the full operating temperature range, otherwise specifications are at VCC = 9.5V, CT = 180pF, TA = TMIN to TMAX unless other wise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillator
OSCT Total Variation VCC = 6.5V to 9.5V ● 236 277 319 kHz OSCV CT RAMP Amplitude Measured on CT 3.6 3.85 4.2 V OSYT SYNC Threshold Measured on SYNC 1.6 1.8 2.2 V OSYW Minimum SYNC Pulse Width Measured at Outputs (Note 2) 6 ns OSYWX Maximum SYNC Pulse Width Measured on Outputs, CT = 180pF 1.3 µs OSOP SYNC Output Pulse Width Measured on SYNC, RSYNC = 5.1k 170 ns
Error Amplifier
VFB FB Input Voltage COMP = 2.5V (Note 3) 1.179 1.204 1.229 V FBI FB Input Range Measured on FB (Note 4) –0.3 2.5 V AVOL Open-Loop Gain COMP = 1V to 3V (Note 3) 70 90 dB IIB Input Bias Current COMP = 2.5V (Note 3) 5 50 nA VOH Output High Load on COMP = –100µA 4.7 4.92 V VOL Output Low Load on COMP = 100µA 0.18 0.4 V ISOURCE Output Source Current COMP = 2.5V – 400 – 800 µA ISINK Output Sink Current COMP = 2.5V 3 7 mA
Reference
VREF Initial Accuracy TA = 25°C, Measured on VREF 4.925 5 5.075 V REFTV Total Variation Line, Load and Temperature ● 4.9 5 5.1 V REFLD Load Regulation Load on VREF = 100µA to 5mA 2 15 mV REFLN Line Regulation VCC = 6.5V to 9.5V 0.1 10 mV REFSC Short-Circuit Current VREF Shorted to GND 18 30 45 mA
Outputs
OUTH(X) Output High Voltage IOUT(X) = –50mA 7.9 8.4 V OUTL(X) Output Low Voltage IOUT(X) = 50mA 0.6 1 V RHI(X) Pull-Up Resistance IOUT(X) = –50mA to –10mA 22 30 Ω RLO(X) Pull-Down Resistance IOUT(X) = –50mA to –10mA 12 20 Ω tr(X) Rise Time COUT(X) = 50pF 5 15 ns tf(X) Fall Time COUT(X) = 50pF 5 15 ns
Current Limit and Shutdown
CLPP Pulse-by-Pulse Current Limit Threshold Measured on CS 0.34 0.415 0.48 V CLSD Shutdown Current Limit Threshold Measured on CS 0.55 0.64 0.73 V SSI Soft-Start Current SS = 2.5V 7 12 17 µA SSR Soft-Start Reset Threshold Measured on SS 0.7 0.4 0.1 V FLT FAULT Reset Threshold Measured on SS 4.4 4.1 3.8 V
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Set FB to –0.3V, 2.5 and insure that COMP does not phase invert. of a device may be impaired.
Note 5:
The LTC1922-1E is guaranteed to meet performance specifications
Note 2:
SYNC pulse width is valid from >20ns and <0.4 • (1/fOSC), from 0°C to 85°C. Specification over the –40°C to 85°C operating VSYNC = 0V to 5V. temperature range are assured by design, characterization and correlation
Note 3:
FB is driven by a servo loop amplifier to control V with statistical process controls. The LTC1922-1I is guaranteed and tested COMP for these tests. over the – 40°C to 85°C operating temperature range. 3