AMIS-52000 Single-Chip Radio Transceiver

Data Sheet

AMI Semiconductor - Confidential

7

www.amis.com

Register

BIT

Bit Name

Bit State

Comments

Register

7

CLKOUT

0

CLKOUT is enabled

0x05

Enable

1

CLKOUT is disabled

Register

4 & 5

CLKOUT

00

Automatic control

0x08

Output

01

RC oscillator is output

Select

10

Xtal oscillator is output

11

CLKOUT output is off

Register

0 & 1

CLKOUT

00

Divide crystal by 4

0x0F

Frequency

01

Divide crystal by 3

Select

10

Divide crystal by 2

11

Divide crystal by 1

VDD, Supply Voltage

The VDD pin is the supply voltage for the AMIS-52000

circuits other than the RF output. It is typically 3.0V DC.

Please refer to section “Operating and Maximum

Specifications” of this specification for operating conditions.

GND, Analog/Digital Ground

The GND pin is a ground connection for all non-RF circuitry.

RFGND, RF Ground

The RFGND pin is a ground connection for all the internal RF

circuitry.

X1, X2, Crystal Oscillator

X1 and X2 connect a parallel resonance oscillator crystal and

capacitors to the AMIS-52000. The AMIS-52000 is designed

with an internal trim function that is controlled by writing to

the AMIS-52000 registers.

LPFILT, Loop Filter

The LPFILT pin connects the AMIS-52000 internal PLL

comparator to the external loop filter. The filter is required

to allow the internal PLL to lock to the crystal frequency

while producing the desired RF frequency. A simple second

order RC loop filter is typically sufficient for this purpose.

VCO1, VCO2, Voltage Controlled Oscillator Tune

The VCO1 and VCO2 pins connect a parallel capacitor

and inductor to the AMIS-52000 internal VCO (Voltage

Controlled Oscillator). The LC circuit tunes the VCO

frequency. The frequency of the VCO is twice the desired

TX or RX frequency and the range of the VCO is 520MHz to

1400MHz.

CLKOUT, Internal Clock Output

The CLKOUT pin output is either the internal RC oscillator,

the crystal oscillator, or a divided version of the crystal

oscillator.

CREF, Current Reference Bias

The CREF pin requires a resistor to ground to set the

bandgap BIAS CURRENT. IT IS CRITICAL THAT THE

RESISTOR BE 33.2K OHMS, 1% or better tolerance.

R(Bias) = 33.2 KΩ (1%)

I

2

CDATA, I

2

CCLK, I

2

C Control Interface Bus

The AMIS-52000 implements an I

2

C serial 8 bit bi-directional

interface with the pins I

2

CDATA and I

2

CCLK. The I

2

C bus

handshaking and protocol is implemented for a SLAVE

device. Because only a minimal configuration is supported,

clock stretching for slow peripherals, general call

addressing, and ten-bit extended addressing are not

implemented. The interface will support either normal (0 -

100 Kbits/second) or fast (0 - 400 Kbits/second) data

modes. The interface conforms to the Phillips specification

for the I

2

C bus.

Reg

Name

Register Function

0x03

TX Crystal Trim

Changing the value of

this changes the crystal frequency

0x04

RX Crystal Trim

Changing the value of

this changes the crystal frequency

NOTE:

The value of the external crystal load capacitors should be slightly

lower than for a typical crystal to allow for capacitor loading in the

trim function.

Table 12: Crystal Divider Control

Table 13: Crystal Divider Control TX/RX Pin Definition Control (Registers 0x05 and 0x08)