3

LTC1291

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Delay Time, CS

See Test Circuits

q

80

150

ns

Delay Time, CLK

See Test Circuits

q

80

200

ns

↑

50

ns

Time Output Data Remains Valid after CLK

↓

130

ns

CLK High Time

300

ns

CLK Low Time

400

ns

See Test Circuits

q

65

130

ns

See Test Circuits

q

25

50

ns

↑

50

ns

Setup Time, CS

↓ before CLK↑

50

ns

CS High Time During Conversion

500

ns

CS Low Time During Data Transfer

18

CLK Cycles

Input Capacitance

Analog Inputs On Channel

100

pF

Analog Inputs Off Channel

5

pF

Digital Inputs

5

pF

Note 7: Two on-chip diodes are tied to each analog input which will

conduct for analog voltages one diode drop below GND or one diode drop

analog inputs (5V) can cause this input diode to conduct, especially at

elevated temperature, and cause errors for inputs near full scale. This spec

allows 50mV forward bias of either diode. This means that as long as the

analog input does not exceed the supply voltage by more than 50mV, the

output code will be correct.

Note 8: Channel leakage current is measured after the channel selection.

Note 9: Increased leakage currents at elevated temperatures cause the

≥ 125kHz at 125°C,

°C.

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: All voltage values are with respect to ground (unless otherwise

noted).

5V, 1LSB = 5V/4096 = 1.22mV.

Note 5: Linearity error is specified between the actual end points of the

A/D transfer curve. The deviation is measured from the center of the

quantization band.

Note 6: Recommended operating conditions.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

High Level Input Voltage

q

2.0

V

Low Level Input Voltage

q

0.8

V

High Level Input Current

q

2.5

µA

Low Level Input Current

q

–2.5

µA

High Level Output Voltage

µA

4.7

V

µA

q

2.4

4.0

V

Low Level Output Voltage

q

0.4

V

High Z Output Leakage

q

3

µA

q

–3

µA

Output Source Current

– 20

mA

Output Sink Current

20

mA

Positive Supply Current

CS High

q

612

mA

LTC1291BC, LTC1291CC, LTC1291DC

q

510

µA

LTC1291BI, LTC1291CI, LTC1291DI,

q

515

µA

LTC1291BM, LTC1291CM, LTC1291DM

LTC1291B/LTC1291C/LTC1291D

(Note 3)

ELECTRICAL C

C

HARA TER STICS

DIGITAL A D

I

DC

LTC1291B/LTC1291C/LTC1291D

CS High

Power shutdown

CLK Off