Cirrus Logic CS5462 - Manual (Page 3)

CS5462
DS547F1 3
1. GENERAL DESCRIPTION
The CS5462 is a CMOS monolithic power mea-
surement device with an energy computation en-
gine. The CS5462 combines a programmable gain
amplifier, two
 ADC’s, system calibration, and
energy-to-frequency conversion circuitry on a sin-
gle chip.
The CS5462 is designed for energy measurement
applications and is optimized to interface to a shunt
or current transformer for current measurement,
and to a resistive divider or transformer for voltage
measurement. The current channel has a pro-
grammable gain amplifier (PGA) which provides
two full-scale input level options. With a single +5 V
supply on VA+/AGND, both of the CS5462’s input
channels accommodate common mode + signal
levels between (AGND - 0.25 V) and VA+.
The CS5462 has three pulse output pins: E1, E2
and FOUT. E1 and E2 can be used to directly drive
a mechanical counter or stepper motor, or inter-
face to a microcontroller. The FOUT pin conveys
average real power at a pulse frequency many
times higher than that of the E1 or E2 pulse fre-
quency, allowing for high speed calibration.
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
Calibration Pins 5, 23 CAL0, CAL1 - Must be tied to a program select pin for calibration.
Program
Selects
1,2,3,4,5,6
4,6,20,22,21,
18,3
P1, P2, P3, P4, P5, P6, P7 - Used in Calibration, Frequency Select, and Input Gain Select.
Frequency Select 7 FREQ - Must be tied to a program select pin to determine the frequency of E1 and E2.
Current Channel Gain
Select 17 IGAIN - Must be tied to a program select pin to determine the Full-Scale Input Voltage Range of
the current channel.
Reset 19 RESET - Low activates Reset
Energy Pulse Outputs
Energy Output 1 4 , 2 3 21, 22 E1, E2 - The energy output pin issues a fixed-width pulse train output with a rate proportional to
real energy.
High Freq Output 5 18 FOUT - Outputs energy pulses at a maximum rate of 10 kHz. Used for calibration purposes.
Negative Energy
Indicator 6
6
NEG - Low indicates negative energy.
VREFIN 12 Voltage Reference Input
VREFOUT 11 Voltage Reference Output
VIN- 10 Differential Voltage Input
VIN+ 9 Differential Voltage Input
DGND 8 Digital Ground
FREQ 7 Frequency Select
NEG / P2 6 Neg Energy Indicator / Prog Sel 2
CAL0 5 Calibration Pin 0
DGND / P1 4 Digital Ground / Prog Sel 1
VD+ / P7 3 Positive Power Supply / Prog Sel 7
CPUCLK 2 CPU Clock Output
XOUT 1 Crystal Out
AGND 13 Analog Ground
VA+ 14 Positive Analog Supply
IIN- 15 Differential Current Input
IIN+ 16 Differential Current Input
IGAIN 17 Gain Select
FOUT / P6 18 High Frequency Output / Prog Sel 6
RESET 19 Reset
P3 20 Program Select 3
E1 / P5 21 Energy Output 1 / Prog Sel 5
E2 / P4 22 Energy Output 2 / Prog Sel 4
CAL1 23 Calibration Pin 1
XIN 24 Crystal In