Owner's manual

CS5467
6 DS714F3
2. PIN DESCRIPTION
Clock Generator
Crystal Out
Crystal In
1,28
XOUT, XIN — Connect to an external quartz crystal. Alternatively, an external clock can be sup-
plied to the XIN pin to provide the system clock for the device.
CPU Clock Output 2
CPUCLK — Logic-level output from crystal oscillator. Can be used to clock an external CPU.
Control Pins and Serial Data I/O
Serial Clock 5
SCLK — Clocks serial data from the SDI pin and to the SDO pin when CS is low. SCLK is a
Schmitt-trigger input when MODE is low and a driven output when MODE is high.
Serial Data Output 6
SDO — Serial data output. Data is clocked out by SCLK.
Chip Select 7
CS — An input that enables the serial interface when MODE is low and a driven output when
MODE is high.
Mode Select 8
MODE — High selects external E
2
PROM, Low selects external microcontroller. MODE includes a
weak internal pull-down and therefore selects microcontroller mode if not connected.
Energy Output
22, 25,
26
E3, E1, E2 — Primarily active-low energy pulse outputs. These can be programmed to output
other conditions.
Reset 23
RESET — An active-low Schmitt-trigger input used to reset the chip.
Interrupt 24
INT — Active-low output, indicates that an enabled condition has occurred.
Serial Data Input 27
SDI — Serial data input. Data is clocked in by SCLK.
Analog Inputs/Outputs
Differential Voltage Inputs
9,10
13, 14
VIN1+, VIN1-, VIN2+, VIN2- — Differential analog inputs for the voltage channels.
Differential Current Inputs
20,19,
16,15
IIN1+, IIN1-, IIN2+, IIN2- — Differential analog inputs for the current channels.
Voltage Reference Output 11
VREFOUT — The on-chip voltage reference output. Nominally 2.5 V, referenced to AGND.
Voltage Reference Input 12
VREFIN — The voltage reference input. Can be connected to VREFOUT or external 2.5 V refer-
ence.
Power Supply Connections
Positive Digital Supply 3
VD+ — The positive digital supply.
Digital Ground 4
DGND — Digital ground.
Positive Analog Supply 18
VA+ — The positive analog supply.
Analog Ground 17
AGND — Analog ground.
Power Fail Monitor 21
PFMON — Used to monitor the unregulated power supply via a resistive divider. If the PFMON
voltage drops below its low limit, the low-supply detect (LSD) bit is set in the Status register.
VREFIN 12Voltage Reference Input
VREFOUT 11Voltage Reference Output
VIN1- 10Differential Voltage Input
VIN1+ 9Differential Voltage Input
MODE 8Mode Select
CS 7Chip Select
SDO 6Serial Data Ouput
SCLK 5Serial Clock
DGND 4Digital Ground
VD+ 3Positive Digital Supply
CPUCLK 2CPU Clock Output
XOUT 1Crystal Out
AGND17 Analog Ground
VA+18 Positive Analog Supply
IIN1-19 Differential Current Input
IIN1+20 Differential Current Input
PFMON21 Power Fail Monitor
E322 Energy Output 3
RESET23 Reset
INT24 Interrupt
E125 Energy Output 1
26
SDI27 Serial Data Input
XIN28 Crystal In
E2
Energy Output 2
VIN2- 14Differential Voltage Input
VIN2+ 13Differential Voltage Input
IIN2-15 Differential Current Input
IIN2+16 Differential Current Input