Datasheet LTC1286, LTC1298 (Analog Devices) - 4

LTC1286/LTC1298
AC CHARACTERISTICS (Note 5) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tSMPL Analog Input Sample Time See Operating Sequence 1.5 CLK Cycles fSMPL(MAX) Maximum Sampling Frequency LTC1286 ● 12.5 kHz LTC1298 ● 11.1 kHz tCONV Conversion Time See Operating Sequence 12 CLK Cycles tdDO Delay Time, CLK↓ to DOUT Data Valid See Test Circuits ● 250 600 ns tdis Delay Time, CS↑ to DOUT Hi-Z See Test Circuits ● 135 300 ns ten Delay Time, CLK↓ to DOUT Enable See Test Circuits ● 75 200 ns thDO Time Output Data Remains Valid After CLK↓ CLOAD = 100pF 230 ns tf DOUT Fall Time See Test Circuits ● 20 75 ns tr DOUT Rise Time See Test Circuits ● 20 75 ns CIN Input Capacitance Analog Inputs, On Channel 20 pF Analog Inputs, Off Channel 5 pF Digital Input 5 pF The ● denotes specifications which apply over the full operating
Note 7:
Two on-chip diodes are tied to each reference and analog input temperature range. which will conduct for reference or analog input voltages one diode drop
Note 1:
Absolute maximum ratings are those values beyond which the life below GND or one diode drop above VCC. This spec allows 50mV forward of a device may be impaired. bias of either diode for 4.5V ≤ VCC ≤ 5.5V. This means that as long as the
Note 2:
All voltage values are with respect to GND. reference or analog input does not exceed the supply voltage by more than
Note 3:
These devices are specified at 5V. For 3V specified devices, see 50mV the output code will be correct. To achieve an absolute 0V to 5V LTC1285 and LTC1288. input voltage range will therefore require a minimum supply voltage of 4.950V over initial tolerance, temperature variations and loading. For 5.5V
Note 4:
Increased leakage currents at elevated temperatures cause the S/H < VCC ≤ 9V, reference and analog input range cannot exceed 5.55V. If to droop, therefore it is recommended that fCLK ≥ 120kHz at 85°C, fCLK ≥ reference and analog input range are greater than 5.55V, the output code 75kHz at 70° and fCLK ≥ 1kHz at 25°C. will not be guaranteed to be correct.
Note 5:
VCC = 5V, VREF = 5V and CLK = 200kHz unless otherwise specified.
Note 8:
The supply voltage range for the LTC1286 is from 4.5V to 9V, but
Note 6:
Linearity error is specified between the actual end points of the the supply voltage range for the LTC1298 is only from 4.5V to 5.5V. A/D transfer curve.
Note 9:
Recommended operating conditions
Note 10:
Channel leakage current is measured after the channel selection.
W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Supply Current vs Clock Supply Current vs Sample Rate Supply Current vs Temperature Rate with CS High and CS Low
1000 450 35 TA = 25°C TA = 25°C V T CC = VREF = 5V A = 25°C 30 VCC = VREF = 5V f V CLK = 200kHz CC = VREF = 5V 400 fCLK = 200kHz 25 100 20 LTC1298 350 15 LTC1286 LTC1298 fSMPL =11.1kHz 10 CS = 0 300 (AFTER CONVERSION) 10 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 5 SUPPLY CURRENT (µA) 250 1 LTC1286 fSMPL =12.5kHz 0.002 CS = VCC 1 200 0 0.1k 1k 10k 100k –55 –35 –15 5 25 45 65 85 105 125 1 20 40 60 80 100 120 140 160 180 200 SAMPLE RATE (kHz) TEMPERATURE (°C) FREQUENCY (kHz) LT1286/98 G03 LT1286/98 G04 LT1286/98 G01 4