9

SCD5028-2 Rev G 5/7/2014

Aeroflex Plainview

-12dB/oct

Gain = 4

-6dB/oct

BW

2G

G

T

(T = G/2)

rad/sec

10T

Closed Loop Bandwidth (BWcl) (Hz) =

-12dB/oct

2G



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FIGURE 4 – RDC5028 OPEN LOOP BODE PLOT

TRANSFER FUNCTION AND BODE PLOT

The dynamic performance of the converter can be determined from its Functional Block Diagram, Transfer

Function Diagram and Bode plots, as shown in Figures 2, 3 and 4.

PROCEDURE FOR SELECTING RDC BANDWIDTH COMPONENTS

*

Input: Carrier Frequency (Fc) in Hz [47 to 30,000 Hz]

Input: Nominal Resolver Input Level in Vrms [1Vrms min. to 1.5Vrms max.]

Input: Resolution in bits; 10, 12, 14 or 16 bits

Input: Closed Loop Bandwidth (BWcl) in Hz

[10 bit; BWcl = Fc/4 max.]

[12 bit; BWcl = Fc/8 max.]

[14 bit; BWcl = Fc/12 max.]

[16 bit; BWcl = Fc/16 max. ]

Input: Maximum Tracking Rate in RPS

[16 bit;

16 RPS max.]

(RPS = rotations per second)

[14 bit,

64 RPS max.]

[12 bit;

256 RPS max.]

[10 bit, 1024 RPS max.]

Input: Hysteresis in LSBs. Recommended is 1 LSB for 16 & 14 bits and 0.7 LSBs for 12 & 10 bits.

EG = Nominal Resolver Input Level

 .0027 [16 bit] or

EG = Nominal Resolver Input Level

 .011 [14 bit] or

EG = Nominal Resolver Input Level

 .043 [12 bit] or

EG = Nominal Resolver Input Level

 .17

[10 bit]

G = 2.22

 BWcl

 0.45  G1  G2

BWcl

Gain = 0.4