Texas Instruments TMS3637P, Data Manual

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5–3
8. After a minimum valid time of t
v
= 10
µ
s, apply the high-voltage programming pulse to
permanently store the 31 code bits in EEPROM memory as shown in Figure 5–2. As stated in
steps 4 and 5, exactly 4 reset and 31 clock pulses must be applied for the device to successfully
program. The device does not transfer the code from its registers into the EEPROM if less than
or greater than 4 reset and 31 clock pulses are used before the programming pulse is applied.
15 V
OSCC
OSCR
(clock in)
VCC
IN
(data in)
OSCR
(clock)
IN
(data in)
C01
C02
C03
C04
C22
CA
CI
tw7
tw6
5 V
th1
>
1
µ
s
tsu4
>
1
µ
s
4 Reset Pulses 22 Security Bits
5.5 V
5 V
tv
9 Configuration Bits
C01– C22 CA– CI
OUT
(previous data)†
tsu3
High-Voltage
Programming Pulse
† Previous data refers to data that was previously programmed into the device. If programmed for first time, this contains
a random test code from the factory.
Figure 5–2. EEPROM Write Mode
5.3 Internal Oscillator Operation for Transmit and Receive Modes Setting
Frequency
The TMS3637 has an internal oscillator that can be used in either the transmit or receive configurations of
the device. The oscillator free-running frequency (f
osc
) is controlled by an external resistor and capacitor
and is determined by:
f
osc
= 5 / (4
×
C
osc
×
R
osc
) (1)
where
C
osc
= capacitor from OSCC to GND
R
osc
= resistor from OSCR to GND
The allowable oscillation range or R
osc
versus V
CC
, and associated f
osc
values, and range versus C
osc
for
three given values of R
osc
are given in Section 4.