© 2009 Microchip Technology Inc. DS21948E-page 1
MCP3905/06
Features
• Supplies active (real) power measurement for
single-phase, residential energy-metering
• Supports the IEC 62053 International Energy
Metering Specification and legacy IEC 1036/
61036/687 Specifications
• Two multi-bit, Digital-to-Analog Converters
(DACs), second-order, 16-bit, Delta-Sigma
Analog-to-Digital Converters (ADCs)
• 0.1% typical measurement error over 500:1
dynamic range (MCP3905)
• 0.1% typical measurement error over 1000:1
dynamic range (MCP3906)
• Programmable Gain Amplifier (PGA) for small-
signal inputs supports low-value shunt current
sensor
-16:1 PGA - MCP3905
-32:1 PGA - MCP3906
• Ultra-low drift on-chip reference: 15 ppm/°C
(typical)
• Direct drive for electromagnetic mechanical
counter and two-phase stepper motors
• Low IDD of 4 mA (typical)
• Tamper output pin for negative power indication
• Industrial Temperature Range: -40°C to +85°C
• Supplies instantaneous active (real) power on
HFOUT for meter calibration
US Patents Pending
Description
The MCP3905/06 devices are energy-metering ICs
designed to support the IEC 62053 International
Metering Standard Specification. They supply a
frequency output proportional to the average active
(real) power, as well as a higher-frequency output
proportional to the instantaneous power for meter
calibration. They include two 16-bit, delta-sigma ADCs
for a wide range of IB and IMAX currents and/or small
shunt (< 200 µOhms) meter designs. It includes an
ultra-low drift voltage reference with < 15 ppm/°C
through a specially designed band gap temperature
curve for the minimum gradient across the industrial
temperature range. A fixed-function DSP block is
on-chip for active (real) power calculation. Strong
output drive for mechanical counters are on-chip to
reduce field failures and mechanical counter sticking. A
no-load threshold block prevents any current creep
measurements. A Power-On Reset (POR) block
restricts meter performance during low-voltage
situations. These accurate energy-metering ICs with
high field reliability are available in the industry-
standard pinout.
Package Type
Functional Block Diagram