Datasheet LTC1291 (Analog Devices) - 3

LTC1291
AC CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. (Note 3) LTC1291B/LTC1291C/LTC1291D SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tdis Delay Time, CS↑ to DOUT Hi-Z See Test Circuits ● 80 150 ns ten Delay Time, CLK↓ to DOUT Enabled See Test Circuits ● 80 200 ns thDI Hold Time, DIN after CLK↑ VCC = 5V (Note 6) 50 ns thDO Time Output Data Remains Valid after CLK↓ 130 ns tWHCLK CLK High Time VCC = 5V (Note 6) 300 ns tWLCLK CLK Low Time VCC = 5V (Note 6) 400 ns tf DOUT Fall Time See Test Circuits ● 65 130 ns tr DOUT Rise Time See Test Circuits ● 25 50 ns tsuDI Setup Time, DIN Stable before CLK↑ VCC = 5V (Note 6) 50 ns tsuCS Setup Time, CS↓ before CLK↑ VCC = 5V (Note 6) 50 ns tWHCS CS High Time During Conversion VCC = 5V (Note 6) 500 ns tWLCS CS Low Time During Data Transfer VCC = 5V (Note 6) 18 CLK Cycles CIN Input Capacitance Analog Inputs On Channel 100 pF Analog Inputs Off Channel 5 pF Digital Inputs 5 pF
U DIGITAL A D DC ELECTRICAL CH C ARA TER S I TICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. (Note 3) LTC1291B/LTC1291C/LTC1291D SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIH High Level Input Voltage VCC = 5.25V ● 2.0 V VIL Low Level Input Voltage VCC = 4.75V ● 0.8 V IIH High Level Input Current VIN = VCC ● 2.5 µA IIL Low Level Input Current VIN = 0V ● –2.5 µA VOH High Level Output Voltage VCC = 4.75V, IOUT = –10µA 4.7 V VCC = 4.75V, IOUT = – 360µA ● 2.4 4.0 V VOL Low Level Output Voltage VCC = 4.75V, IOUT = 1.6mA ● 0.4 V IOZ High Z Output Leakage VOUT = VCC, CS High ● 3 µA VOUT = 0V, CS High ● – 3 µA ISOURCE Output Source Current VOUT = 0V – 20 mA ISINK Output Sink Current VOUT = VCC 20 mA ICC Positive Supply Current CS High ● 6 12 mA CS High Power Shutdown CLK Off ● 5 10 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 7:
Two on-chip diodes are tied to each analog input which will of a device may be impaired. conduct for analog voltages one diode drop below GND or one diode drop above V
Note 2:
All voltage values are with respect to ground (unless otherwise CC. Be careful during testing at low VCC levels (4.5V), as high level analog inputs (5V) can cause this input diode to conduct, especially at noted). elevated temperature, and cause errors for inputs near full scale. This spec
Note 3:
VCC = 5V, CLK = 1.0MHz unless otherwise specified. allows 50mV forward bias of either diode. This means that as long as the
Note 4:
One LSB is equal to VCC divided by 4096. For example, when VCC = analog input does not exceed the supply voltage by more than 50mV, the 5V, 1LSB = 5V/4096 = 1.22mV. output code will be correct.
Note 5:
Linearity error is specified between the actual end points of the
Note 8
: Channel leakage current is measured after the channel selection. A/D transfer curve. The deviation is measured from the center of the quantization band.
Note 9:
Increased leakage currents at elevated temperatures cause the S/H to droop, therefore it is recommended that f
Note 6:
Recommended operating conditions. CLK ≥ 125kHz at 125°C, fCLK ≥ 30kHz at 85°C and fCLK ≥ 3kHz at 25°C. 1291fa 3