PLL Control

This page will describe how to control the PLL on common GMRS/FRS/PMR/LPD UHF 2-way radios.
Controlling the PLL gives the ability to customized TX and/or RX frequency.

Known PLL’s so far:

  • Gaintech GP214D
  • Samsung S1T8825
  • Toshiba TP31202
  • MC Devices MCD8825B
  • Panasonic AN6311

Gaintech GP214D

Everything you need to know is in the datasheet: LINK

Samsung S1T8825

Everything you need to know is in the datasheet: LINK

Toshiba TP31202

Everything you need to know is in the datasheet: TB31202

MC Devices MCD8825B

Everything you need to know is in the datasheet: MCD8825B

Download the GP214D/S1T8825/TP31202/MCD8825B PLL Calculator (Excel Sheet):

GP214D PLL Calculator
GP214D PLL Calculator
GP214D_Calculator.xls
23.6 KB
860 Downloads
Details

Panasonic AN6311

No datasheet available.

AN6311 Pinout:

The AN6311 is used for example in ALAN-445 Sport radio. See schematic:

ALAN-445 Sport Schematic
ALAN-445 Sport Schematic
ALAN445-circuit-diagram.pdf
297.8 KB
923 Downloads
Details

.:: How to control the AN6311 PLL ::.

  • Three control signals are required: CLKIN, DATAIN, EN
    • Pins: CLKIN = 56, DATAIN = 55, EN = 1
  • Three types of frames are used:
    • 1 Frame to set reference counter – Length 17 bit
    • 1 Frame to with configuration bits – Length 18 bit
    • 1 Frame to set the programmable and swallow counter – Length 19 bit
  • Frames will be transferred MSB first

Bus timing

  • CLKIN t1 = 2us; t0 = 10us
  • DATAIN changes 2us before CLKIN rising edge
  • DATAIN goes LO 6us after last CLKIN falling edge
  • EN goes HI 2us after last DATAIN falling edge
  • EN t1 = 2us
  • Delay between two frames 100us

Init sequence

  • Power up
  • CLKIN & EN = LO while DATAIN = HI for 1-2 seconds, depends on radio CPU startup
  1. Frame = set reference counter; 0x99A7 for 6.25 KHz channel spacing
    50us pause
  2. Frame = set reference counter; 0x99A7 for 6.25 KHz channel spacing
    300us pause
  3. Frame = set PLL configuration; 0x02E805 for RX
    100us pause
  4. Frame = set programmable and swallow counter; 0x0469A9 for 451.8625 MHz = RX FRS chan 1
    800us pause
  5. Frame = set PLL configuration; 0x02E805 for RX
    100us pause
  6. Frame = set programmable and swallow counter; 0x0469A9 for 451.8625 MHz = RX FRS chan 1

Offset between RX and TX frequency depends on intermediate frequency used in RX stage.

Set TX mode and frequency

  1. Frame = set PLL configuration; 0x02E005 for TX
    100us pause
  2. Frame = set programmable and swallow counter; 0x048469 for 462.5625 MHz = TX FRS chan 1
    100us pause
  3. Frame = set PLL configuration; 0x02E205 for RX
    100us pause
  4. Frame = set PLL configuration; 0x02E205 for TX

End TX and set back to RX frequency

  1. Frame = set PLL configuration; 0x02E805 for RX
    100us pause
  2. Frame = set programmable and swallow counter; 0x0469A9 for 451.8625 MHz = RX FRS chan 1

Frame description (what is known so far)

  • Frame to set reference counter, 17-bit

01001100110100111

Unknown
Reference counter
, 001100110100 = 0x334 = 820
Register code

  • Frame to set frequency, 19-bit

1000110100110101001

11-bit programmable counter, 10001101001 = 0x469 = 1129
5-bit swallow counter, 10101 = 0x15 = 21
Register code

.:: How to calculate PLL counters for desired TX frequency ::.

Things you need to know:

  • PLL oscillator frequency, ie. 10.25MHz
  • Channel spacing, ie. 6.25KHz
  • TX frequency, ie. FRS channel 1 = 462.5625MHz

1. Calculate reference counter

Reference counter = PLL oscillator frequency / Channel spacing / 2
Reference counter = 10.25MHz / 6.25KHz / 2 = 820

2. Calculate total divide ratio

Total divide ratio = TX frequency / Channel spacing
Total divide ratio = 462.5625MHz / 6.25KHz = 74010

3. Calculate programmable counter

Programmable counter = (Total divide ration / 2) / 32
Programmable counter = (74010 / 2) / 32 = 1156

4. Calculate swallow counter

Swallow counter = (Total divide ration / 2) – (32 * Programmable counter)
Swallow counter = (74010 / 2) – (32 * 1156) = 13

.:: How to calculate PLL counters for desired RX frequency ::.

To calculate the RX frequency from a known TX frequency, you need to know the intermediate frequency used in the RX stage of the radio, for example 10.7MHz or 21.4Mhz.

Example:

  • PLL oscillator frequency, ie. 10.25MHz
  • Channel spacing, ie. 6.25KHz
  • TX frequency, ie. FRS channel 1 = 462.5625MHz
  • Intermediate frequency 10.7MHz

1. Calculate RX frequency

RX frequency = TX frequency – Intermediate frequency
RX frequency = 462.5625MHz – 10.7MHz = 451.8625MHz

2. Calculate reference counter

Reference counter = PLL oscillator frequency / Channel spacing / 2
Reference counter = 10.25MHz / 6.25KHz / 2 = 820

3. Calculate total divide ratio

Total divide ratio = TX frequency / Channel spacing
Total divide ratio = 451.8625MHz / 6.25KHz = 72298

4. Calculate programmable counter

Programmable counter = (Total divide ration / 2) / 32
Programmable counter = (72298 / 2) / 32 = 1129

5. Calculate swallow counter

Swallow counter = (Total divide ration / 2) – (32 * Programmable counter)
Swallow counter = (72298 / 2) – (32 * 1129) = 21

Download the AN6311 PLL Calculator (Excel Sheet):

AN6311 PLL Calculator
AN6311 PLL Calculator
AN6311_Calculator.xls
23.6 KB
759 Downloads
Details

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