AD2S1205

Rev. A | Page 7 of 20

Pin No.

Mnemonic

Description

26

B

Incremental Encoder Emulation Output B. Logic output. This output is free running and is valid if the resolver format

input signals applied to the converter are valid.

27

NM

North Marker Incremental Encoder Emulation Output. Logic output. This output is free running and is valid if the

resolver format input signals applied to the converter are valid.

28

DIR

Direction. Logic output. This output is used in conjunction with the incremental encoder emulation outputs. The

DIR output indicates the direction of the input rotation and is high for increasing angular rotation.

29

DOS

Degradation of Signal. Logic output. Degradation of signal (DOS) is detected when either resolver input (Sin or Cos)

exceeds the specified DOS Sin/Cos threshold. See the Signal Degradation Detection section. DOS is indicated by a

logic low on the DOS pin and is not latched when the input signals exceed the maximum input level.

30

LOT

Loss of Tracking. Logic output. LOT is indicated by a logic low on the LOT pin and is not latched. See the Loss of

Signal Detection section.

31

FS1

Frequency Select 1. Logic input. FSI in conjunction with FS2 allows the frequency of EXC/EXC to be programmed.

32

FS2

Frequency Select 2. Logic input. FS2 in conjunction with FS1 allows the frequency of EXC/EXC to be programmed.

33

RESET

the specified operating range of 4.5 V to 5.5 V. See the

section.

Supply Sequencing and Reset

34

EXC

Excitiation Frequency. Analog output. An on-board oscillator provides the sinusoidal excitation signal (EXC) and its

complement signal (EXC) to the resolver. The frequency of this reference signal is programmable via the FS1 and FS2 pins.

35

EXC

Excitation Frequency Complement. Analog output. An on-board oscillator provides the sinusoidal excitation signal

(EXC) and its complement signal (EXC) to the resolver. The frequency of this reference signal is programmable via

the FS1 and FS2 pins.

36, 42

AGND

Analog Ground. These pins are ground reference points for analog circuitry on the AD2S1205. All analog input

signals and any external reference signal should be referred to this AGND voltage. Both of these pins should be

connected to the AGND plane of a system. The AGND and DGND voltages should ideally be at the same potential

and must not be more than 0.3 V apart, even on a transient basis.

37

Sin

Positive Analog Input of Differential Sin/SinLO Pair. The input range is 2.3 V p-p to 4.0 V p-p.

38

SinLO

Negative Analog Input of Differential Sin/SinLO Pair. The input range is 2.3 V p-p to 4.0 V p-p.

39

Analog Supply Voltage, 4.75 V to 5.25 V. This pin is the supply voltage for all analog circuitry on the AD2S1205. The

transient basis.

40

CosLO

Negative Analog Input of Differential Cos/CosLO Pair.

41

Cos

Positive Analog Input of Differential Cos/CosLO Pair.

43

REFBYP

Reference Bypass. Reference decoupling capacitors should be connected here. Typical recommended values are

10 μF and 0.01 μF.

44

REFOUT

Voltage Reference Output, 2.39 V to 2.52 V.