X9110_08 Datasheet, PDF (3/18 Pages) Intersil Corporation – Dual Supply/Low Power/1024-Tap/SPI Bus

X9110
Circuit Level Applications
• Vary the gain of a voltage amplifier
• Provide programmable dc reference voltages for
comparators and detectors
• Control the volume in audio circuits
• Trim out the offset voltage error in a voltage amplifier
circuit
• Set the output voltage of a voltage regulator
• Trim the resistance in Wheatstone bridge circuits
• Control the gain, characteristic frequency and Q-factor in
filter circuits
• Set the scale factor and zero point in sensor signal
conditioning circuits
• Vary the frequency and duty cycle of timer ICs
• Vary the dc biasing of a pin diode attenuator in RF circuits
• Provide a control variable (I, V, or R) in feedback circuits
System Level Applications
• Adjust the contrast in LCD displays
• Control the power level of LED transmitters in
communication systems
• Set and regulate the DC biasing point in an RF power
amplifier in wireless systems
• Control the gain in audio and home entertainment systems
• Provide the variable DC bias for tuners in RF wireless
systems
• Set the operating points in temperature control systems
• Control the operating point for sensors in industrial
systems
• Trim offset and gain errors in artificial intelligent systems
Pin Descriptions
PIN
(TSSOP)
1
2
3
4
5
6
7
8
SYMBOL
V+
SO
A0
SCK
WP
SI
V_SS
V-
FUNCTION
Analog Supply Voltage
Serial Data Output
Device Address
Serial Clock
Hardware Write Protect
Serial Data Input
System Ground
Analog Supply Voltage
9
CS
Chip Select
10
HOLD Device Select. Pause the Serial Bus
Pin Descriptions (Continued)
PIN
(TSSOP)
SYMBOL
FUNCTION
11
R_W
Wiper Terminal of the Potentiometer
12
R_H
High Terminal of the Potentiometer
13
R_L
Low Terminal of the Potentiometer
14
V_CC
System Supply Voltage
Bus Interface Pins
SERIAL OUTPUT (SO)
SO is a serial data output pin. During a read cycle, data is
shifted out on this pin. Data is clocked out on the falling edge
of the serial clock.
SERIAL INPUT (SI)
SI is the serial data input pin. All opcodes, byte addresses
and data to be written to the pots and pot registers are input
on this pin. Data is latched by the rising edge of the serial
clock.
SERIAL CLOCK (SCK)
The SCK input is used to clock data into and out of the
X9110.
HOLD (HOLD)
HOLD is used in conjunction with the CS pin to select the
device. Once the part is selected and a serial sequence is
underway, HOLD may be used to pause the serial
communication with the controller without resetting the serial
sequence. To pause, HOLD must be brought LOW while SCK is
LOW. To resume communication, HOLD is brought HIGH, again
while SCK is LOW. If the pause feature is not used, HOLD should
be held HIGH at all times.
DEVICE ADDRESS (A0)
The address input is used to set the 8-bit slave address. A
match in the slave address serial data stream A0 must be
made with the address input (A0) in order to initiate
communication with the X9110.
CHIP SELECT (CS)
When CS is HIGH, the X9110 is deselected and the SO pin
is at high impedance, and (unless an internal write cycle is
underway) the device will be in the standby state. CS LOW
enables the X9110, placing it in the active power mode. It
should be noted that after a power-up, a HIGH to LOW
transition on CS is required prior to the start of any
operation.
HARDWARE WRITE PROTECT INPUT (WP)
The WP pin when LOW prevents nonvolatile writes to the
Data Registers.
3
FN8158.3
February 13, 2008