Texas Instruments TMS3637P, Data Manual

Page: 23 / 53

5–5
+
–
IN
(Ai)
Amplifier
178
Ω
(internal)
35.5 k
Ω
(internal)
CEX
+ +
R1
R2
Comparator
0.15 nF
(internal)
200-mV Reference
(internal)
(Ao)
+
_
Figure 5–3. Amplifier/Comparator Schematic
5.7 Internal Amplifier/Comparator Test Mode
Normally, the output of the amplifier/comparator section is fed directly to the logic circuitry internal to the
device; however, the output of the amplifier/comparator can be sampled external to the device during the
amplifier test mode to determine if the amplitude and shape of the received signal is acceptable for the
application. To enter the amplifier test mode, apply V
CC
+ 0.5 V to OSCC and apply three or more low-level
pulses to OSCR. This can be done by simply brushing a wire connected from OSCR to GND. The output
of the amplifier stage is then connected internally to TIME, where it can be sampled for evaluation purposes.
5.8 Mode and Configuration Overview
The TMS3637 device is designed to function in many modes and configurations. The device has five primary
modes of operation as shown in Table 5–1.
Table 5–1. Mode and Test Configuration
MODE DESCRIPTION
1 Amplifier Test
2 Program
3 Read
4 Transmitter
5 Receiver
In the transmitter and receiver modes (see Tables 5–2 and 5–3), there are a total of 66 configurations
available, 48 in the receiver mode and 18 in the transmitter mode.