TRF6900
SINGLE-CHIP RF TRANSCEIVER
SLAS213C – SEPTEMBER 1999 – REVISED MAY 2000
Terminal Functions (Continued)
TERMINAL
NAME
I/O
DESCRIPTION
NO.
18
DDS_VCC
DEM_GND
DEM_TANK
DEM_VCC
DIG_GND
DIG_VCC
IF_GND
Direct digital synthesizer supply voltage
Quadrature demodulator ground
Quadrature demodulator tank connection
Quadrature demodulator supply voltage
Digital ground
38
34, 35
36
I/O
21
20
Digital supply voltage
40
Intermediate frequency (IF) section ground
st
Single-ended input for the 1 intermediate frequency (IF) amplifier
IF1_IN
42
I
O
I
st
Single-ended output for the 1 intermediate frequency (IF) amplifier
IF1_OUT
IF2_IN
41
nd
39
Single-ended input for the 2 IF amplifier/limiter
LNA_GND
LNA_IN
1, 3
2
Low-noise amplifier ground
I
Low-noise amplifier input
LNA_OUT
LNA_VCC
LOCKDET
MIX_GND
MIX_IN
47
O
Low-noise amplifier output, open collector
Low-noise amplifier supply voltage
PLL lock detect output, active high. PLL locked when LOCKDET=1.
Mixer ground
48
11
O
43
46
I
Single-ended RF mixer input
MIX_OUT
MIX_VCC
MODE
44
O
Single-ended RF mixer output
Mixer supply voltage
45
17
I
Mode select input. The functionality of the device in Mode0 or Mode1 can be programmed via the A-, B-, C-,
and D-word of the serial control interface.
GND
22
6
Ground
PA_GND
PA_OUT
PA_VCC
PD_OUT1
PD_OUT2
PD_SET
Power amplifier ground
5
O
Power amplifier output, open collector
Power amplifier supply voltage
Charge pump output – PLL in locked condition
Charge pump output – PLL in unlocked condition
4
10
9
O
O
8
Charge pump current setting terminal. An external resistor, R , is connected to this terminal to set the
PD
nominal charge pump current.
PLL ground
PLL_GND
PLL_VCC
RSSI_OUT
S&H_CAP
7
12
33
29
PLL supply voltage
O
Receive strength signal indicator, analog output
I/O
Connection for sample and hold capacitor for the data slicer. This capacitor determines the integration time
constant of the integrator while in the learning mode.
STDBY
16
I
Standby control for the TRF6900, active low. While STDBY=0, the contents of the control registers are still
valid and can be programmed via the serial control interface.
STROBE
TX_DATA
VCO_TANK1
VCO_TANK2
VREF
25
19
13
14
37
23
24
I
I
Serial interface strobe signal
Digital modulation input for FSK/FM modulation of the carrier, active high
VCO tank circuit connection. Should be left open if an external VCO is used.
VCO tank circuit connection. May also be used to input an external VCO signal.
Reference voltage for the quadrature demodulator
I
I
I
XOSC1
O
I
Reference crystal oscillator connection
XOSC2
Reference crystal oscillator connection. May be used as a single-ended clock input if an external crystal
is not used.
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
