CRD5463PM Cirrus Logic Inc, CRD5463PM Datasheet - Page 3

• Manufacturer Part Number: CRD5463PM
• Description: Power Management Modules & Development Tools Ref Design for Power Meter/Monitor
• Manufacturer: Cirrus Logic Inc

Specifications of CRD5463PM

• Interface Type: SPI, UART, USB
• Maximum Operating Temperature: + 85 C
• Operating Supply Voltage: 90 VAC to 260 VAC
• Product: Power Management Development Tools
• For Use With/related Products: CS5463
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2. SYSTEM OVERVIEW
As illustrated in Figure 1, the CRD5463PM is composed of voltage and current sensors, a CS5463 power
measurement device, an ATtiny2313 microcontroller, opto-coupler isolation, and UART-USB converter.
2.1 DC Power Supplies
There are two isolated +5V DC power domains in the CRD. One is converted from AC power lines through
capacitor-dropper AC/DC power supply and provides +5VDC supply to the CS5463 and MCU. The other
is directly from PC through USB interface and provides +5VDC to the UART-USB converter.
This capacitor type of DC power supply is very low-cost but not efficient. Total power consumption drew
from the AC line is 2.3 Watt and 79mA (tested with 240 VAC input).
2.2 Voltage Sensor
The high AC line voltage must be converted to small voltage signal before being applied onto the CS5463
voltage channel inputs (VIN±). The CRD5463PM uses resistor voltage divider as the voltage sensor.
The divider ratio is determined by the maximum V
channel. The maximum input range of the CS5463 voltage channel is 176 mV RMS. The division ratio
shall be chosen to satisfy the equation:
To leave some margin, the Vout is normally set around 150 mVrms with the maximum V
CRD5463PM, R2 is 1 kΩ. R1 is composed of four 422 kΩ resistors to increase the total voltage rating of
the voltage sensor.
When V
DS805RD2
V
I
in
= 260 V RMS, V
Voltage & Current
Sensors
Figure 3. CRD5463PM Resistive Divider Voltage Sensor
out
Figure 2. CRD5463PM Simplified Block Diagram
= 260 V × 1 / [1 + (4 × 422)] = 154 mV RMS.
Measurement
Vin
CS5463
Vin
Power
max
×
R
R
R
1
1
2
AC/DC
R
Interrupt
+
in
Reset
2
R
SPI
and the maximum input range of the CS5463 voltage
2
<
176
MCU
mVrms
Vout
UART
Vout
UART
=
Vin
CRD5463PM
UART -
USB
×
R
1
R
+
2
R
in
2
. In the
U
S
B
3