MCP3909 datasheet(29/44 Pages) MICROCHIP

Part #	MCP3909

Description	Energy Metering IC with SPI Interface and Active Power Pulse Output

PDF	44 Pages

Scroll/Zoom	100%

Manufacturer	MICROCHIP [Microchip Technology]

Direct Link	http://www.microchip.com

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29 / 44 page

DS22025B-page 29

MCP3909

5.6

Filter Input Mode

The filter input mode allows the user to feed the

MCP3909 device an input to the LPF1. Data is

received MSB first. The MCP3909 will treat this data

as if it were the output of the multiplier and will LPF

and D-F the result as normal, giving the resulting

output frequency on HFOUT, FOUT0 and FOUT1. See

Tables 4-2 and 4-3 for transfer functions of the output

frequencies.

When using filter input mode, the user must wait for

the data ready flag (DR) to appear on SDO before

attempting to clock in data to the device. The user can

not access either the multiplier output or the dual

channel output while in this mode.

FIGURE 5-6:

Filter Input Mode.

D3 D2

D1 D0

Hi-z

D16

D18 D17

17 18

19 20

X 20

D19

Hi-z

F1 / SDI

F2 / SCK

NEG / SDO

F0 / CS

MCP3909 Datasheet(PDF) 29 Page - Microchip Technology