cs5566 Cirrus Logic, Inc., cs5566 Datasheet - Page 26

• Manufacturer Part Number: cs5566
• Description: ?2.5 V / 5 V, 5 Ksps, 24-bit ?? Adc
• Manufacturer: Cirrus Logic, Inc.

4. PIN DESCRIPTIONS
26
VREF+, VREF- – Voltage Reference Input, Pin 9, 10
AIN+, AIN- – Differential Analog Input, Pin 4, 5
SMODE – Serial Mode Select, Pin 3
BUFEN – Buffer Enable, Pin 8
TST – Factory Test, Pin 2
V1+ – Positive Power 1, Pin 7
V1- – Negative Power 1, Pin 6
Voltage Reference Input
Voltage Reference Input
Differential Analog Input
Differential Analog Input
CS – Chip Select, Pin 1
Bipolar/Unipolar Select
Serial Mode Select
Sleep Mode Select
Negative Power 1
The Chip Select pin allows an external device to access the serial port. If SMODE = VL (SSC
Mode) and CS is held high, the SDO output and the SCLK output will be held in a
high-impedance output state.
Factory test only. Connect to VLR.
The serial interface mode pin (SMODE) dictates whether the serial port behaves as a master or
slave interface. If SMODE is tied high (to VL), the port will operate in the Synchronous
Self-Clocking (SSC) mode. In SSC mode, the port acts as a master in which the converter out-
puts both the SDO and SCLK signals. If SMODE is tied low (to VLR), the port will operate in the
Synchronous External Clocking (SEC) mode. In SEC mode, the port acts as a slave in which
the external logic or microcontroller generates the SCLK used to output the conversion data
word from the SDO pin.
AIN+ and AIN- are differential inputs for the converter.
The V1- and V2- pins provide a negative supply voltage to the core circuitry of the chip. These
two pins should be decoupled as shown in the application block diagrams. V1- and V2- should
be supplied from the same source voltage. For single-supply operation, these two voltages are
nominally 0 V (Ground). For dual-supply operation, they are nominally -2.5 V.
The V1+ and V2+ pins provide a positive supply voltage to the core circuitry of the chip. These
two pins should be decoupled as shown in the application block diagrams. V1+ and V2+ should
be supplied from the same source voltage. For single supply-operation, these two voltages are
nominally +5 V. For dual-supply operation, they are nominally +2.5 V.
Buffers on input pins AIN+ and AIN- are enabled if BUFEN is connected to V1+ and disabled if
connected to V1-.
A differential voltage reference input on these pins functions as the voltage reference for the
converter. The voltage between these pins can range between 2.4 volts and 4.2 volts, with
4.096 volts being the nominal reference voltage value.
Positive Power 1
Buffer Enable
Factory Test
Chip Select
SMODE
BUFEN
SLEEP
VREF+
BP/UP
VREF-
AIN+
AIN-
TST
V1+
V1-
CS
1
2
3
4
5
6
7
8
9
10
11
12
3/26/08
24
23
22
21
20
19
18
17
16
15
14
13
RDY
SCLK
SDO
VL
VLR
MCLK
V2-
V2+
DCR
CONV
VLR2
RST
Ready
Serial Clock Input/Output
Serial Data Output
Logic Interface Power
Logic Interface Return
Master Clock
Negative Voltage 2
Positive Voltage 2
Digital Core Regulator
Convert
Logic Interface Return
Reset
CS5566
DS806PP1