CS5466
4 DS659F2
2. PIN DESCRIPTION
Clock Generator
Crystal Out
Crystal In
1, 24
XOUT, XIN - A single stage amplifier 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 clock can be
supplied to the XIN pin to provide the system clock for the device.
CPU Clock Output 2
CPUCLK - Output of on-chip oscillator which can drive one standard CMOS load.
Control Pins
Gain Select 5, 7
IGAIN1, IGAIN0 - Used to select the current channel input gain range.
Frequency Select 17, 20, 23
FREQ2,FREQ1,FREQ0 - Used to select max pulse output frequency for E1, E2, and FOUT.
High Pass Filter Enable 8
HPF - High disables the HPF. Low activates HPF on Voltage channel. Connecting HPF pin to
FOUT pin activates HPF on Current channel.
Reset 19
RESET - Low activates Reset.
Energy Pulse Outputs
Energy Output 22, 21
E1, E2 - Active low alternating pulses with an output frequency that is proportional to the active
(real) power.
High Freq Output 18
FOUT - Outputs energy pulses at a frequency higher than E1 and E2 outputs. Used for calibra-
tion purposes.
Neg Energy Indicator 6
NEG - High indicates negative energy.
Analog Inputs/Outputs
Differential Voltage Inputs 9, 10
VIN+, VIN- - Differential analog input pins for voltage channel.
Voltage Reference
Output
11
VREFOUT - The on-chip voltage reference output pin. The voltage reference has a nominal
magnitude of 2.5 V and is referenced to the AGND pin on the converter.
Voltage Reference Input 12
VREFIN - Voltage input to this pin establishes the voltage reference for the on-chip modulators.
Differential Current Inputs 16, 15
IIN+, IIN- - Differential analog input pins for current channel.
Power Supply Connections
Positive Digital Supply 3
VD+ - The positive digital supply.
Digital Ground 4
DGND - Digital Ground.
Analog Ground 13
AGND - Analog Ground.
Positive Analog Supply 14
VA+ - The positive analog supply.
VREFIN 12Voltage Reference Input
VREFOUT 11Voltage Reference Output
VIN- 10Differential Voltage Input
VIN+ 9Differential Voltage Input
HPF 8High-pass Filter Enable
IGAIN1 7Gain Select 1
NEG 6Negative Energy Indicator
IGAIN0 5Gain Select 0
DGND 4Digital Ground
VD+ 3Positive Power Supply
CPUCLK 2CPU Clock Output
XOUT 1Crystal Out
AGND13 Analog Ground
VA+14 Positive Analog Supply
IIN-15 Differential Current Input
IIN+16 Differential Current Input
FREQ217 Frequency Select 2
FOUT18 High-frequency Output
RESET19 Reset
FREQ120 Frequency Select 1
E221 Energy Output 2
E122 Energy Output 1
FREQ023 Frequency Select 0
XIN24 Crystal In
