Texas Instruments TMS3637P, Data Manual

Page: 41 / 53

6–9
Table 6–5. Infrared Receiver Component Functions (Modulated Transmission Mode)
DEVICE FUNCTION
U1 Demodulator TDA3048 (or equivalent)
U2 TMS3637 configured as a normal logic (1-code) Q-state inverting receiver
R1 Current-limiting resistor for U1
R2 Resistor on TIME that, in conjunction with C2, determines OUT pulse duration on U2.
R3 Resistor on OSCR that, in conjunction with C3, determines the internal oscillator frequency of U2.
R4 Power-supply current-limiting resistor
C1 Power-supply filter capacitor
C2 Capacitor on TIME that, in conjunction with R2, determines OUT pulse duration on U2.
C3 Capacitor on OSCC that, in conjunction with R3, determines the internal oscillator frequency of U2.
Q1 Infrared phototransistor for received code
D2 Diode that is used to prevent back-EMF in L2 from sourcing current to OUT.
L2 Coil of relay R1
RY1 Relay, 12 V, SPDT
R2
22 k
Ω
OSCR OSCC TIME GND
C7
1 nF
VCC IN CEX OUT
U2 (receiver)
R2
1 M
Ω
C2
470 nF
D2
VCC
C1
100
µ
F
+
47 nF
47 nF
10 k
Ω
10 k
Ω
47 nF 47 nF
L2
RY1
R4
10
Ω
R1
22
Ω
1.5 nF
10 nH
6.3 nF
22 nF
Q1
12 V
U1 (TDA3048)
8 7 6 5
1 2 3 4
Figure 6–6. Infrared Modulated Receiver