CS5462 datasheet(14/18 Pages) CIRRUS

14 / 18 page

CS5462

which time the CS5462 will configure itself and re-

sume normal operation.

4.6

Oscillator Characteristics

XIN and XOUT are the input and output of an in-

verting amplifier which can provide oscillation and

can be configured as an on-chip oscillator, as

shown in Figure 8. The oscillator circuit is designed

to work with a quartz crystal or a ceramic resona-

tor. To reduce circuit cost, two load capacitors C1

and C2 are integrated in the device, one between

XIN and DGND, one between XOUT and DGND.

Lead lengths should be minimized to reduce stray

capacitance. To drive the device from an external

clock source, XOUT should be left unconnected

while XIN is driven by the external circuitry. There

is an amplifier between XIN and the digital section

which provides CMOS level signals. This amplifier

works with sinusoidal inputs so there are no prob-

lems with slow edge times.

4.7

User Defined Settings

EXAMPLE: Design a hybrid stepper motor meter

with an 2 Hz maximum pulse output frequency on

the E1, E2 pins with 500 mVP-P signal on the in-

puts of the current and voltage channels and the

high pass filter enabled on the current channel

only. Using the figure below these settings can be

selected with two connections.

By directly connecting FREQ with P4 and IGAIN

with P5 the CS5462 is configured to drive a step-

per motor with a maximum pulse output rate of

2 Hz, to support an input range of 50 0mVP-P, and

to remove all DC content on the current signals by

enabling the HPFs on the Ich. The CS5462 is now

ready for calibration.

Before applying power to the chip, connect the

CAL0 and CAL1 pins to P4. This will select

0% + 0% = 0% gain adjustment. After making this

connection the CS5462 is ready to be calibrated.

Once power is applied the CS5462 will begin a

startup sequence in which it will scan the FREQ,

IGAIN, CAL0, and CAL1 pins. After determining

which connections are made the FREQ, IGAIN,

CAL0, and CAL1 pins will become high impedance

inputs and the part will begin normal operation and

start converting. If on-chip calibration is required

place known voltages across the inputs on IIN±

and VIN±.

For example, 150 mVRMS = ~424.26 mVP-P will be

used for both the current and voltage inputs.

424.26 mVP-P is ~84.853% of the maximum full

scale input of both the current and voltage chan-

nels. With this input on both channels the expected

pulse

output

frequency

84.853% * 84.853% = 72% of full scale. This

Reset

Normal

Operation

5 V

4 V

2.5 V

1 V

0 V

Time

Supply

Voltage

Figure 7. Power-on Reset

Oscillator

Circuit

DGND

XIN

XOUT

C1 =

22 pF

C2 =

Figure 8. Oscillator Connection

10x

50x

10x

50x

10x

CAL1

CAL0

0.25 Hz (stp)

FREQ

+4.2%

+2.8%

+1.4

-1.4%

-2.8%

-4.2%

IGAIN

+0.6%

+0.4%

+0.2%

-0.2%

-0.4%

-0.6%

0.5 Hz (stp)

1 Hz (stp)

2 Hz (stp)

4 Hz (stp)

4 Hz (mc)

16 Hz (mc)

500mV

100mV

500mV

100mV

500mV

no hpf

hpf both

hpf Ich

hpf Vch

hpf Ich

Figure 9. Calibration, Frequency Select, and

PGA Select

CS5462 датащи(PDF) 14 Page - Cirrus Logic

CS5462 датащи(HTML) 14 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

датащи скачать

ссылки URL