uaa3515a NXP Semiconductors, uaa3515a Datasheet - Page 17

• Manufacturer Part Number: uaa3515a
• Description: 900 Mhz Analog Cordless Telephone Ic
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7.7
Pin V
RX and TX PLLs. It is regulated at 2.7 V nominal voltage.
Two capacitors of 4.7 F and 100 nF must be connected
to pin V
tolerance of the regulated voltage is initially 8% but is
improved to 2% after the internal bandgap voltage
reference is adjusted through the microcontroller.
7.8
The low-battery detector measures the voltage level of the
V
input of the comparator is connected to VB, the other to the
middle point of the resistance divider. The comparator has
a built-in hysteresis to prevent spurious switching. The
precision of the detection depends on the divider
accuracy, the comparator offset and the accuracy of the
reference voltage VB. The output is multiplexed at pin
CDLBD. When the battery voltage level is under the
threshold voltage the output CDLBD is going LOW.
2002 Sep 09
CC
900 MHz analog cordless telephone IC
using a resistance divider and a comparator. One
REG
Voltage regulator
Low-battery detection
REG
provides the internal supply voltage for the
to filter and stabilize this regulated voltage. The
17
7.9
The DATA, CLK and EN pins provide a 3-wire
unidirectional serial interface for programming the
reference counters, the transmit and receive channel
divider-counters and the control functions.
The interface consists of 19-bit shift registers connected to
a matrix of registers organized as 7 words of 16 bits (all
are control registers). The leading 16 bits include the data
D15 to D0. The trailing 3 bits set up the address AD2 to
AD0. The data is entered with the most significant bit D15
first and the last bit is AD0.
Pins DATA and CLK are used to load data into the shift
register. Figure 10 shows the timing required on all pins.
Data is clocked into the shift registers on negative clock
transitions.
A new clock divider ratio is enabled using an extra EN
rising edge. Minimum hold time is 50 ns and during this
time no clock cycle is allowed. These extra EN edges can
be applied to all the data programmed but will have no
effect on the serial interface programming.
The pins DATA, CLK and EN are supplied by V
ESD protection diodes on these pins are connected to
V
CC
.
Microcontroller interface
Product specification
UAA3515A
REG
. The