LTC2460/LTC2462
6
24602fa
pin FuncTions
REFOUT (Pin 1): Reference Output Pin. Nominally 1.25V,
this voltage sets the fullscale input range of the ADC. For
noise and reference stability connect to a 0.1µF capacitor
tied to GND. This capacitor value must be less than or
equal to the capacitor tied to the reference compensation
pin (COMP). REFOUT cannot be overdriven by an external
reference. For applications that require an input range
greater than 0V to 1.25V, please refer to the LTC2450/
LTC2452.
COMP (Pin 2): Internal Reference Compensation Pin. For
low noise and reference stability, tie a 0.1μF capacitor to
GND.
CS (Pin 3): Chip Select (Active LOW) Digital Input. A LOW
on this pin enables the SDO output. A HIGH on this pin
places the SDO output pin in a high impedance state and
any inputs on SDI and SCK will be ignored.
SDI (Pin 4): Serial Data Input Pin. This pin is used to pro-
gram the sleep mode and 30Hz/60Hz output rate (LTC2460).
SCK (Pin 5): Serial Clock Input. SCK synchronizes the
serial data input/output. Once the conversion is complete,
a new data bit is produced at the SDO pin following each
SCK falling edge. Data is shifted into the SDI pin on each
rising edge of SCK.
SDO (Pin 6): Three-State Serial Data Output. SDO is used
for serial data output during the DATA INPUT/OUTPUT
state and can be used to monitor the conversion status.
GND (Pins 7, 11): Ground. Connect directly to the ground
plane through a low impedance connection.
REF
–
(Pin 8): Negative Reference Input to the ADC. The
voltage on this pin sets the zero input to the ADC. This
pin should tie directly to ground or the ground sense of
the input sensor.
IN
+
(LTC2462), IN (LTC2460) (Pin 9): Positive input volt-
age for the LTC2462 differential device. ADC input for the
LTC2460 single-ended device.
IN
–
(LTC2462), GND (LTC2460) (Pin 10): Negative input
voltage for the LTC2462 differential device. GND for the
LTC2460 single-ended device.
V
CC
(Pin 12): Positive Supply Voltage. Bypass to GND with
a 10μF capacitor in parallel with a low-series-inductance
0.1μF capacitor located as close to the device as possible.
Exposed Pad (Pin 13 – DFN Package): Ground. Connect
directly to the ground plane through a low impedance
connection.
Typical perForMance characTerisTics
(T
A
= 25°C, unless otherwise noted)
Power Supply Rejection
vs Frequency at V
CC
Conversion Time vs Temperature
FREQUENCY AT V
CC
(Hz)
1
REJECTION (dB)
24602 G10
–20
–40
–60
–80
–100
–120
10
1k 10k 100k 1M
100
10M
TEMPERATURE (°C)
–50
24602 G11
20
16
17
18
19
15
14
–25
25 50 75
0
V
CC
= 5V, 4.1V, 3V
V
REF
vs V
CC
2.0 3.52.5 4.03.0 5.0 5.54.5 6.0
V
CC
(V)
REF
1.24891
24602 G12
1.24884
1.24885
1.24886
1.24887
1.24888
1.24889
1.24890
T
A
= 25°C