Cirrus Logic CS5451A - Manual (Page 3)

CS5451A
DS635F4 3
1. PIN DESCRIPTION
Clock Generator
Master Clock Input 25 XIN - External clock signal or oscillator input.
Control Pins and Serial Data I/O
Serial Clock Output
1
SCLK - Serial port clock signal that determines the output data rate for SDO pin. Rate of SCLK is
dependent on the XIN frequency and state of OWRS pin.
Serial Data Output 2 SDO -Serial port data output pin. Data will be output at a rate defined by SCLK.
Frame Sync 3 FSO - Framing signal indicates when data samples are about to be transmitted on the SDO pin.
Serial Port Enable 4 SE - When SE is low, the output pins of the serial port are tri-stated.
Current Input Gain
5
GAIN - A logic high sets current channel gain to 1, a logic low sets the gain to 20. If no connection
is made to this pin, it will default to logic low level (through internal 200 k
 resistor to DGND).
Output Word Rate Select
23
OWRS - A logic low sets the output word rate (OWR) to XIN/2048 (Hz). A logic high sets the
OWR to XIN/1024 (Hz). If no connection is made to this pin, then OWRS will default to logic low
level (through internal 200 k
 resistor to DGND).
Reset 24 RESET - Low activates Reset, all internal registers are set to their default states.
Analog Inputs/Outputs
Voltage Reference Input 7 VREFIN - The input to this pin establishes the voltage reference for the on-chip modulator.
Voltage Reference Output
8
VREFOUT - The on-chip voltage reference output. The voltage reference has a nominal magni-
tude of 1.2 V and is referenced to the AGND pin on the converter.
Differential Voltage Inputs 11,12
18,17
22,21
VIN3+, VIN3- - Differential analog input pins for the voltage channel 3.
VIN2+, VIN2- - Differential analog input pins for the voltage channel 2.
VIN1+, VIN1- - Differential analog input pins for the voltage channel 1.
Differential Current Inputs 13,14
16,15
20,19
IIN3+, IIN3- - Differential analog input pins for the current channel 3.
IIN2+, IIN2- - Differential analog input pins for the current channel 2.
IIN1+, IIN1- - Differential analog input pins for the current channel 1.
Power Supply Connections
Analog Ground 6 AGND - Analog ground.
Positive Analog Supply 9 VA+ - The positive analog supply. Typical +3 V ±10% relative to AGND.
Negative Analog Supply 10 VA- - The negative analog supply. Typical -2 V ±10% relative to AGND.
Charge Pump Drive
26
CPD - Designed to drive external charge pump circuitry that will produce a negative analog sup-
ply (VA-)voltage.
Digital Ground 27 DGND - Digital Ground.
Positive Digital Supply 28 VD+ - The positive digital supply. Typical +3 V ±10% relative to AGND.
1
14
7
13
6
12
5
11
9
4
3
8
10
2
15
18
16
24
20
19
25
21
17
26
27
22
28
23
IIN2-
VIN2+
IIN2+
RESET
IIN1+
IIN1-
XIN
VIN1-
VIN2-
CPD
DGND
VIN1+
VD+
OWRS
IIN3-
VIN3+
IIN3+
GAIN
VA+
VA -
SE
VREFOUT
VIN3-
FSO
SDO
VREFIN
SCLK
AGND
Differential Current Input 2
Differential Voltage Input 2
Differential Current Input 2
Reset
Differential Current Input 1
Differential Current Input 1
Master Clock
Differential Voltage Input 1
Differential Voltage Input 2
Charge Pump Drive
Digital Ground
Differential Voltage Input 1
Digital Supply
Output Word Rate Select
Differential Current Input 3
Differential Voltage Input 3
Differential Current Input 3
Current Input Gain
Positive Analog Supply
Negative Analog Supply
Serial Port Enable
Reference Output
Differential Voltage Input 3
Frame Sync
Serial Data Output
Reference Input
Serial Clock Output
Analog Ground
CS5451A