TS7001
PIN FUNCTIONS
PIN
LABEL
CS
DESCRIPTION
Chip Select: As an active low logic input signal, the CS input provides the dual function of
initiating TS7001 conversions as well as framing the serial data transfer. When the TS7001
is operated in Mode 1(its default power management mode), the CS pin also acts as the
shutdown pin in that the TS7001 is powered-down when the CS pin is logic high.
Power Supply Voltage: The TS7001’s V
DD
range +2.7V to +3.6V. In two-channel operation,
the VDD pin also serves as the TS7001’s voltage reference source during conversions. For
optimal performance, the VDD pin should be bypassed to GND with a
10-µF tantalum capacitor in parallel with a 0.1µF ceramic capacitor.
Analog Ground Pin: The GND pin is the ground reference point for all TS7001 internal
circuitry. In systems with separate AGND and DGND planes, the TS7001’s GND pin
should be connected to the AGND plane.
Analog Input Channel 1/External VREF Input: In single-channel mode, the AIN1/VREF pin
is configured as VREFIN/OUT. In this mode, the TS7001’s internal 2.5V reference can be
accessed or an external reference can be applied to this pin thereby overriding the internal
reference. The reference voltage range for an externally-applied reference is 1.2V to VDD.
In two-channel mode, the AIN1/VREF pin operates as a second analog input channel,
AIN1. The input voltage range on AIN1 is 0 to VDD.
Analog Input Channel 0: In single-channel operation, AIN0 is the TS7001’s analog input
with an input voltage range of 0V to VREF. In two-channel operation, the AIN0 pin exhibits
an analog input range of 0V to VDD.
Serial Data Input: Serial data to be loaded into the TS7001’s control register is applied at
the DIN pin. Serial data is loaded into the ADC from the host processor on low-to-high
SCLK transitions (see the Control Register section for additional information). Configuring
the TS7001 as a single-channel, read-only ADC can be achieved by hard-wiring the DIN
pin to GND or by applying a logic LOW at all times at the DIN pin.
Serial Data Output: The TS7001’s conversion result is available on this pin. Serial data is
transferred out of the TS7887 on high-to low transitions of SCLK. The 12-bit conversion
result is comprised of four leading zeros followed by the 12 bits of conversion data
formatted MSB first. Thus, a total of 16 SCLK high-to-low transitions transfers the
conversion result to the host processor as shown in the corresponding timing diagram of
Figure 14.
Serial-Clock Input: SCLK is used for (3) purposes: a) to load serial data from the host
processor into the TS7001’s control register on low-to-high SCLK transitions; b) to transfer
the 12-bit conversion result to the host processor on high-to-low SCLK transitions; and c)
to control the TS7001’s conversion process.
1
2
VDD
3
GND
4
AIN1/VREF
5
AIN0
6
DIN
7
DOUT
8
SCLK
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TS7001DS r1p0
RTFDS
TOUCHSTONE [ TOUCHSTONE SEMICONDUCTOR INC ]
