CS5460A
6. PIN DESCRIPTION
Crystal Out
XOUT
CPUCLK
VD+
1
24
23
22
21
20
19
18
17
16
15
14
13
XIN
Crystal In
CPU Clock Output
Positive Digital Supply
Digital Ground
SDI
Serial Data Input
2
EDIR
EOUT
INT
Energy Direction Indicator
Energy Output
3
DGND
SCLK
SDO
4
Serial Clock Input
Serial Data Output
Chip Select
Interrupt
5
RESET
NC
Reset
6
CS
No Connect
7
Mode Select
MODE
VIN+
PFMON
IIN+
IIN-
Power Fail Monitor
Differential Current Input
Differential Current Input
Positive Analog Supply
Analog Ground
8
Differential Voltage Input
Differential Voltage Input
9
VIN-
10
11
12
Voltage Reference Output VREFOUT
Voltage Reference Input VREFIN
VA+
VA-
Clock Generator
1,24
2
XOUT, XIN - A gate inside the chip is connected to these pins and can be used with a
crystal to provide the system clock for the device. Alternatively, an external (CMOS
compatible clock) can be supplied into XIN pin to provide the system clock for the device.
Crystal Out
Crystal In
CPUCLK - Output of on-chip oscillator which can drive one standard CMOS load.
CPU Clock Output
Control Pins and Serial Data I/O
5
SCLK - A clock signal on this pin determines the input and output rate of the data for the
SDI and SDO pins respectively. This input is a Schmitt trigger to allow for slow rise time
signals. The SCLK pin will recognize clocks only when CS is low.
Serial Clock Input
6
7
8
SDO - SDO is the output pin of the serial data port. Its output will be in a high impedance
state when CS is high.
Serial Data Output
Chip Select
CS - When low, the port will recognize SCLK. An active high on this pin forces the SDO
pin to a high impedance state. CS should be changed when SCLK is low.
MODE - When at logic high, the CS5460A can perform the auto-boot sequence with the
aid of an external serial EEPROM to receive commands and settings. When at logic low,
the CS5460A assumes normal “host mode” operation. This pin is pulled down to logic
low if left unconnected, by an internal pull-down resistor to DGND.
Mode Select
20
21
22
INT - When INT goes low it signals that an enabled event has occurred. INT is cleared
(logic 1) by writing the appropriate command to the CS5460A.
Interrupt
EOUT - The energy output pin output a fixed-width pulse rate output with a rate (pro-
grammable) proportional to real (billable) energy.
Energy Output
Energy Direction
Indicator
EDIR - The energy direction indicator indicates if the measured energy is negative.
SDI - the input pin of the serial data port. Data will be input at a rate determined by SCLK.
23
Serial Data Input
Measurement and Reference Input
9,10
VIN+, VIN- - Differential analog input pins for voltage channel.
Differential
Voltage Inputs
51
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