CS5462

5

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

∆Σ 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 micro controller. 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

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

21, 22

E1, E2 - The energy output pin issues a fixed-width pulse train output with a rate proportional to

real energy.

18

FOUT - Outputs energy pulses at a maximum rate of 10 kHz. Used for calibration purposes.

Negative Energy

6

NEG - Low indicates negative energy.

Analog Inputs/Outputs

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