TI TLV1570CPW

TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
D
D
D
D
D
D
D
D
D
D
D
D
D
Fast Throughput Rate: 1.25 MSPS at 5 V,
625 KSPS at 3 V
Wide Analog Channel Input: 0 V to AVDD
Eight Analog Input Channels
Channel Auto-Scan
Differential Nonlinearity Error: < ±1 LSB
Integral Nonlinearity Error: < ±1 LSB
Signal-to-Noise and Distortion Ratio: 57 dB
Single 2.7-V to 5.5-V Supply Operation
Very Low Power: 40 mW at 5.5 V,
8 mW at 2.7 V
Auto-Power Down: 300 µA Max
Software Power Down: 10 µA Max
Glueless Serial Interface to TMS320 DSPs
and (Q)SPI Compatible Microcontrollers
Programmable Internal Reference Voltage:
3.8-V Reference for 5-V Operation,
2.3-V Reference for 3-V Operation
applications
D
D
D
D
D
D
Mass Storage and Hard Disk Drive
Automotive
Digital Servos
Process Control
General Purpose DSP
Image Sensor Processing
DW OR PW PACKAGE
(TOP VIEW)
CH4
CH3
CH2
CH1
CH0
DVDD
DGND
FS
SCLK
SDIN
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
AIN
MO
CH5
CH6
CH7
AVDD
AGND
REF
CS
SDOUT
description
The TLV1570 is a 10-bit data acquisition system that combines an 8-channel input multiplexer (MUX), a
high-speed 10-bit ADC, an on-chip reference, and a high-speed serial interface. The device contains an on-chip
control register allowing control of channel selection, conversion start, reference voltage levels, and power
down via the serial port. The MUX is independently accessible, which allows the user to insert a signal
conditioning circuit such as an anti-aliasing filter or an amplifier, if required, between the MUX and the ADC.
Therefore one signal conditioning circuit can be used for all eight channels.
The TLV1570 operates from a single 2.7-V to 5.5-V power supply. The device accepts an analog input range
from 0 V to AVDD and digitizes the input at a maximum 1.25 MSPS throughput rate. Power dissipation is only
8 mW with a 2.7-V supply or 40 mW with a 5.5-V supply. The device features an auto-power down mode that
automatically powers down to 300 µA, 10 ns after a conversion is performed. With software power down
enabled, the device is further powered down to only 10 µA.
The TLV1570 communicates with digital microprocessors via a simple 4- or 5-wire serial port that interfaces
directly to Texas Instruments TMS320 DSPs, and SPI and QSPI compatible microcontrollers without using
additional glue logic.
A very high throughput rate, a simple serial interface, and low power consumption make the TLV1570 an ideal
choice for high-speed digital signal processing requiring multiple analog inputs.
AVAILABLE OPTIONS
PACKAGED DEVICES
TA
SMALL OUTLINE
(DW)
SMALL OUTLINE
(PW)
0°C to 70°C
TLV1570CDW
TLV1570CPW
– 40°C to 85°C
TLV1570IDW
TLV1570IPW
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SPI and QSPI are trademarks of Motorola, Inc.
Copyright  1998, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
functional block diagram
AVDD
MO
AIN
DVDD
REFERENCE
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
REF
REF+
MUX
10-BIT
SAR ADC
REF–
AGND
SCLK
SDIN
SDOUT
I/O REGISTERS
AND CONTROL LOGIC
FS
CS
AGND
DGND
Terminal Functions
TERMINAL
NAME
NO.
AGND
14
AIN
20
AVDD
CH0 – CH7
I/O
DESCRIPTION
Analog ground
I
15
ADC analog input
Analog supply voltage, 2.7 V to 5.5 V
5,4,3,2,1,
18,17,16
I
Analog input channels 0 – 7
CS
12
I
Chip Select. A low level signal on CS enables the TLV1570. A high level signal on CS disables the device
and disconnects power to the TLV1570.
DGND
7
Digital ground
DVDD
6
Digital supply voltage, 2.7 V to 5.5 V
FS
8
I
Frame sync. The falling edge of the frame sync pulse from a DSP indicates the start of a serial data frame
shifted out of the TLV1570. FS is pulled high when interfaced to a microcontroller.
MO
19
O
On-chip MUX analog output
REF
13
I
Reference voltage input. The voltage applied to REF defines the input span of the TLV1570. In external
reference mode, a 0.1 µF decoupling capacitor must be placed between the reference and AGND. This
is not required for internal reference mode.
SCLK
9
I
Serial clock input. SCLK synchronizes the serial data transfer and is also used for internal data conversion.
SDIN
10
I
Serial data input used to configure the internal control register.
SDOUT
11
O
Serial data output. A/D conversion results are output at SDOUT.
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
detailed description
analog-to-digital converter
The TLV1570 ADC uses the SAR architecture described in this section. The CMOS threshold detector in the
successive-approximation conversion system determines the value of each bit by examining the charge on a
series of binary-weighted capacitors (see Figure 1). In the first phase of the conversion process, the analog input
is sampled by closing the SC switch and all ST switches simultaneously. This action charges all of the capacitors
to the input voltage.
SC
Threshold
Detector
To Output
Latches
512
Node 512
REF –
256
128
8
REF+
REF+
REF+
REF –
ST
REF –
ST
REF –
ST
4
2
REF+
REF –
ST
1
REF+
REF –
ST
1
REF+
REF –
ST
REF+
REF –
ST
ST
VI
NOTE: REF– is tied to AGND
Figure 1. Simplified Model of the Successive-Approximation System
In the next phase of the conversion process, all ST and SC switches are opened and the threshold detector
begins identifying bits by identifying the charge (voltage) on each capacitor relative to the reference (REF–)
voltage (REF– is tied to AGND). In the switching sequence, ten capacitors are examined separately until all ten
bits are identified and then the charge-convert sequence is repeated. In the first step of the conversion phase,
the threshold detector looks at the first capacitor (weight = 512). Node 512 of this capacitor is switched to the
REF+ voltage, and the equivalent nodes of all the other capacitors on the ladder are switched to REF–. If the
voltage at the summing node is greater than the trip point of the threshold detector (approximately one-half VCC),
a bit 0 is placed in the output register and the 512-weight capacitor is switched to REF–. If the voltage at the
summing node is less than the trip point of the threshold detector, a bit 1 is placed in the register and the
512-weight capacitor remains connected to REF+ through the remainder of the successive-approximation
process. The process is repeated for the 256-weight capacitor, the 128-weight capacitor, and so forth down the
line until all bits are counted.
With each step of the successive-approximation process, the initial charge is redistributed among the
capacitors. The conversion process relies on charge redistribution to count and weigh the bits from MSB to LSB.
In the case of the TLV1570, REF– is tied to ground and REF+ is connected to the REF input.
The TLV1570 can be programmed to use the on-chip internal reference (DI6=1). The user can select between
two values of internal reference, 2.3 V or 3.8 V, using the control bit DI5.
During internal reference mode, the reference voltage is not output on the REF pin. Therefore it cannot be
decoupled to analog ground (AGND), which acts as the negative reference for the ADC, using an external
capacitor. Hence this mode requires the ground noise to be very low. The REF pin can be left open in this mode.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
sampling frequency, fs
The TLV1570 requires 16 SCLKs for each sampling and conversion, therefore the equivalent maximum
sampling frequency achievable with a given SCLK frequency is:
fs(MAX) = (1/16)fSCLK
power down
The TLV1570 offers two different power-down options. With auto power-down mode enabled, (DI4=0) the ADC
proceeds to power down if FS is not detected on the 17th falling SCLK edge of a cycle (a cycle starts with FS
being detected on a falling edge of SCLK) in DSP mode and after 16 SCLKs in µC mode. The TLV1570 will
recover from auto power down when FS goes high in DSP mode or when the next SCLK comes in µC mode.
In the case of software power down, the ADC goes to the software power-down state one cycle after CR.DI15
is set to 1. Unlike auto power down which recovers in 1 SCLK, software power down takes 16 SCLKs to recover.
Maximum power down dissipation current
300 µA
SOFTWARE
POWERDOWN
CS = DVDD
10 µA
Comparator
Power down
Powerdown
Clock buffer†
Power down
Powerdown
Reference
Active
Powerdown
Register
Not saved
Not saved
Minimum power down time
1 SCLK
1 µs
Minimum resume time
DESCRIPTION
Power down
Power up
AUTO POWER DOWN
1 SCLK
800 ns
DSP mode
No FS present one SCLK after previous conversion completed
CR.DI15 set to 1
Microprocessor mode (FS = 1)
SCLK stopped after previous conversion completed
CR.DI15 set to 1
DSP mode
FS present
CR.DI15 set to 1
Microprocessor mode (FS = 1)
SCLK present
CR.DI15 set to 1
† Only in DSP mode is input buffer of clock in power-down mode.
‡ The software power down enable/disable bit is not acted until the start of the next cycle (see section configuring the TLV1570 for more information.
configuring the TLV1570
The TLV1570 is to be configured by writing the control bits to SDIN. The configuration will not take affect until
the next cycle. A new configuration is needed for each conversion. Once the channel input and other options
are selected, the conversion takes place in the next cycle. Conversion results are shifted out as conversion
progresses ( see Figure 2).
One Cycle
Second Cycle
17
32
SCLK
ts
SDIN
SDOUT
tconv
ts
Configure Data 1
tconv
Configure Data 2
Result 0
Result 1
Figure 2. TLV1570 Configuration Cycle Timing
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
configuration register (CR) definition
BIT
DESCRIPTION
5V
3V
X
X
X
X
Reads out values of the internal register, 1 – read. Only DI15 – DI1 are read out.
X
X
These two bits select the self-test voltage to be applied to the ADC input during next clock cycle:
X
X
X
X
X
X
X
X
X
X
Software power down:
DI15
DI14
DI13, DI12
0:
1:
Normal
Power down enabled
00:
Allow AIN to come in normally
01:
Apply AGND to AIN
10:
Apply VREF/2 to AIN
11:
N/A
Choose speed application
DI11
0:
High speed (higher power consumption)
1:
Low speed (lower power consumption)
This bit enables channel auto-scan function.
DI10
0:
1:
Auto-scan disabled
Auto-scan enabled
DI9 – DI7 These three bits select which of the eight DI9, DI8 These two bits select the channel swept
channels is to be used (if DI10 = 0).
sequence used by auto scan mode (if DI10 = 1)
DI9, DI8, DI7
000:
Channel 0 selected as input
00:
Analog inputs CH0, CH1, CH2, ….., CH7
sequentially selected
001:
Channel 1 selected as input
01:
Analog inputs CH1, CH3, CH5, CH7
sequentially selected
010:
Channel 2 selected as input
10:
Analog inputs CH0, CH2, CH4, CH6
sequentially selected
011:
Channel 3 selected as input
11:
Analog inputs CH7, CH6, CH5, ….., CH0
sequentially selected
100:
Channel 4 selected as input
101:
Channel 5 selected as input
0:
No reset
110:
Channel 6 selected as input
1:
Reset autoscan sequence
111:
Channel 7 selected as input
DI7 Auto-scan reset
Selects Internal or external reference voltage:
DI6
0:
1:
External
Internal
Selects internal reference voltage value to be applied to the ADC during next conversion cycle.
DI5
0:
2.3 V
1:
3.8 V
X
X
Enables/disables auto-power down function:
DI4
1:
Enable
0:
Disable
X
X
X
X
DI2
Performance optimizer – linearity
0: AVDD = 5.5 V to 3.6 V
1: AVDD = 3.5 V to 2.7 V
Always write 0 (reserved bit)
X
X
DI1
Always write 0 (reserved bit)
X
X
DI0
Always write 0 (reserved bit)
X
X
DI3
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
initialization-software sequence
This sequence shows the default settings, unless otherwise specified. The ADC requires that the user write to
it every cycle. There is a cycle delay before control bits are implemented.
Example 1. Normal Sample Mode With Internal Reference
CYCLE
WRITE TO
SDIN
CHANNEL
SAMPLED
OUPUT FROM
SDOUT
COMMENT
1st
0040h
N/A
Invalid
No analog input channel sampled
2nd
01C0h
N/A
Invalid
No analog input channel sampled
3rd
0040h
3
From Channel 3
4th
8040h
0
From Channel 0
Software power down enabled
5th
0040h
N/A
Invalid
Software power down mode, no analog input channel sampled
Recovery time, no analog input channel sampled (16 SCLKs if AVDD = 5 V and
fCLK = 20 MHz)
Wait 800 ns
6th
0140h
N/A
7th
0040h
2
Invalid
Recovery time, no analog input channel sampled
From Channel 2
Example 2. Auto Scan Mode
CYCLE
WRITE TO
SDIN
CHANNEL
SAMPLED
OUTPUT FROM
SDOUT
COMMENT
1st
0480h
N/A
Invalid
Auto-scan reset enabled, no analog input channel sampled
2nd
0480h
N/A
Invalid
No analog input channel sampled
3rd
0400h
0
From Channel 0
4th
0400h
1
From Channel 1
5th
0400h
2
From Channel 2
6th
0400h
3
From Channel 3
7th
0400h
4
From Channel 4
8th
0400h
5
From Channel 5
9th
0400h
6
From Channel 6
10th
0400h
7
From Channel 7
11th
0400h
0
From Channel 0
NOTE: If software power down is enabled during auto-scan mode, the next channel in the sequence is skipped.
6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
initialization-software sequence (continued)
Example 3. Auto-Scan Mode
This example shows a change in sequence in the middle of the current sequence. The following shows that after
the initial auto-scan reset, a reset is not necessary again when switching channel sequences.
CYCLE
WRITE TO
SDIN
CHANNEL
SAMPLED
OUTPUT FROM
SDOUT
COMMENT
1st
0480h
N/A
N/A
No analog input channel sampled
2nd
0480h
N/A
N/A
Auto-scan reset enabled, no analog input channel sampled
3rd
0400h
0
From Channel 0
Start of sequence 0
4th
0700h
1
From Channel 1
Enable channel sequence 3 (no auto-scan reset required)
5th
0700h
7
From Channel 7
Start of sequence 3
6th
0700h
6
From Channel 6
7th
0700h
5
From Channel 5
8th
0700h
4
From Channel 4
9th
0700h
3
From Channel 3
10th
0700h
2
From Channel 2
11th
0700h
1
From Channel 1
12th
0700h
0
From Channel 0
Example 4. Auto-Scan Mode
This example shows a switch in sequence in the course of a sequence. The following shows that a particular
sequence does not have to be continued if remaining channels do not need to be sampled (i.e., only channel
1 through channel 5 sampled, not channels 6, 7, 8)
CYCLE
WRITE TO
SDIN
CHANNEL
SAMPLED
OUPUT FROM
SDOUT
COMMENT
1st
0480h
N/A
N/A
No analog input channel sampled
2nd
0480h
N/A
N/A
Auto-scan reset enabled, no analog input channel sampled
3rd
0400h
0
From Channel 0
4th
0400h
1
From Channel 1
5th
0400h
2
From Channel 2
6th
0400h
3
From Channel 3
7th
0400h
4
From Channel 4
8th
0480h
5
From Channel 5
Auto-scan reset enabled
9th
0400h
0
From Channel 0
Sequence is reset to channel 0
10th
0400h
1
From Channel 1
11th
0400h
2
From Channel 2
The TLV1570 is a 800-ns 10-bit 8-analog input channel analog-to-digital converter with a throughput of up to
1.25 MSPS at 5 V and up to 625 KSPS at 3 V respectively. To run at its fastest conversion rate, it must be clocked
at 20 MHz at 5-V or 10 MHz at 3-V. The TLV1570 can be easily interfaced to microcontrollers, ASICs, DSPs,
or shift registers. The TLV1570 serial interface is designed to be fully compatible with Serial Peripheral Interface
(SPI) and TMS320 DSP serial ports. No additional hardware is required to interface between the TLV1570 and
a microcontroller (µCs) with a SPI serial port or a TMS320 DSP. However, the speed is limited by the SCLK rate
of the µC or the DSP.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
initialization-software sequence (continued)
The TLV1570 interfaces to a DSP over five lines: CS, SCLK, SDOUT, SDIN, and FS, and interfaces to a µC over
four lines: CS, SCLK, SDOUT, and SDIN. The FS input should be pulled high in µC mode. The device is in 3-state
and power-down mode when CS is high. After CS falls, the TLV1570 checks the FS input at the CS falling edge
to determine the operation mode. If FS is low, DSP mode is set, otherwise µC mode is set.
TLV1570
TMS320
CS
XF
CLKX
SCLK
CLKR
FSX
FS
FSR
SDIN
DX
SDOUT
DR
Figure 3. DSP to TLV1570 Interface
µC
TLV1570
CS
I/O Terminal
SCLK
SCLK
DVDD
FS
SDIN
DX
SDOUT
DR
Figure 4. µC to TLV1570 Interface
grounding and decoupling considerations
General practices should apply to the PCB design to limit high frequency transients and noise that are fed back
into the supply and reference lines (see Figure 5). This requires that the supply and reference pins be sufficiently
bypassed. In most cases 0.1 µF ceramic chip capacitors are adequate to keep the impedance low over a wide
frequency range. Since their effectiveness depends largely on the proximity to the individual supply pin. They
should be placed as close to the supply pins as possible.
To reduce high frequency and noise coupling, it is highly recommended that digital and analog ground be
shorted immediately outside the package. This can be accomplished by running a low impedance line between
DGND and AGND, under the package.
TLV1570
DVDD
AVDD
DGND
AGND
100 nF
100 nF
100 nF
REF
Figure 5. Placement of Decoupling Capacitors
8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
power supply ground layout
Printed circuit boards that use separate analog and digital ground planes offer the best system performance.
Wire-wrap boards do not perform well and should not be used. The two ground planes should be connected
together at the low-impedance power-supply source. The best ground connection may be achieved by
connecting the ADC AGND terminal to the system analog ground plane making sure that analog ground
currents are well managed.
simplified analog input analysis
Using the equivalent circuit in Figure 6, the time required to charge the analog input capacitance from 0 to VS
within 1/2 LSB, tch(1/2 LSB), can be derived as follows:
ǒ
Ǔ
The capacitance charging voltage is given by:
V
C(t)
+ VS 1–e–tchńRtCi
where
(1)
Rt = Rs + Ri
Ri = Ri(ADC) + Ri(MUX)
tch = Charge time
The input impedance Ri is 718 Ω at 5 V, and is higher (~ 1.25 kΩ) at 2.7 V. The final voltage to 1/2 LSB is given
by:
(2)
VC (1/2 LSB) = VS – (VS /2048)
ǒ
Ǔ
Equating equation 1 to equation 2 and solving for cycle time tc gives:
V
S
*
ǒ
V
Ǔ
ń2048 + VS 1–e–tchńRtCi
S
and time to change to 1/2 LSB (minimum sampling time) is:
(3)
tch (1/2 LSB) = Rt × Ci × ln(2048)
where
ln(2048) = 7.625
Therefore, with the values given, the time for the analog input signal to settle is:
tch (1/2 LSB) = (Rs + 718 Ω) × 15 pF × ln(2048)
(4)
This time must be less than the converter sample time shown in the timing diagrams. Which is 6x SCLK.
tch (1/2 LSB) ≤ 6x 1/f(SCLK)
(5)
Therefore the maximum SCLK frequency is:
Max(f(SCLK) ) = 6 / tch (1/2 LSB) = 6/(ln(2048) × Rt × Ci )
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
(6)
9
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
simplified analog input analysis (continued)
Driving Source†
TLC1570
MO
Rs
VS
VI
Ri(MUX)
AIN
Ri(ADC)
VC
Ci
15 pF
VI = Input Voltage at AIN
VS = External Driving Source Voltage
Rs = Source Resistance
Ri(ADC)= Input Resistance of ADC
Ri(MUX)= Input Resistance (MUX on resistance)
Ci = Input Capacitance
VC = Capacitance Charging Voltage
† Driving source requirements:
• Noise and distortion for the source must be equivalent to the resolution of the converter.
• Rs must be real at the input frequency.
Figure 6. Equivalent Input Circuit Including the Driving Source
definitions of specifications and terminology
integral nonlinearity (INL)
Integral nonlinearity refers to the deviation of each individual code from a line drawn from zero through full scale.
The point used as zero occurs 1/2 LSB before the first code transition. The full scale point is defined as level
1/2 LSB beyond the last code transition. The deviation is measured from the center of each particular code to
the true straight line between these two points.
differential nonlinearity (DNL)
An ideal ADC exhibits code transitions that are exactly 1 LSB apart. DNL is the deviation from this ideal value.
A differential nonlinearity error of less than ±1 LSB ensures no missing codes.
zero offset
The major carry transition should occur when the analog input is at zero volts. Zero error is defined as the
deviation of the actual transition from that point.
gain error
The first code transition should occur at an analog value 1/2 LSB above negative full scale. The last transition
should occur at an analog value 1 1/2 LSB below the nominal full scale. Gain error is the deviation of the actual
difference between first and last code transitions and the ideal difference between first and last code transitions.
signal-to-noise ratio + distortion (SINAD)
SINAD is the ratio of the rms value of the measured input signal to the rms sum of all other spectral components
below the Nyquist frequency, including harmonics but excluding dc. The value for SINAD is expressed in
decibels.
effective number of bits (ENOB)
For a sine wave, SINAD can be expressed in terms of the number of bits. Using the following formula,
N = (SINAD – 1.76)/6.02
It is possible to get a measure of performance expressed as N, the effective number of bits. Thus, effective
number of bits for a device for sine wave inputs at a given input frequency can be calculated directly from its
measured SINAD.
10
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
definitions of specifications and terminology (continued)
total harmonic distortion (THD)
Total harmonic distortion is the ratio of the rms sum of the first six harmonic components to the rms value of the
measured input signal and is expressed as a percentage or in decibels.
spurious free dynamic range (SFDR)
Spurious free dynamic range is the difference in dB between the rms amplitude of the input signal and the peak
spurious signal.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage range, AGND to AVDD, DGND to DVDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 6.5 V
Analog input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to AVDD+0.3 V
Reference input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AVDD+0.3 V
Digital input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to DVDD+0.3 V
Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 150°C
Operating free-air temperature range, TA: TLV1570C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
TLV1570I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 85°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
recommended operating conditions
power supplies
MIN
TYP
MAX
UNIT
Analog supply voltage, AVDD (see Note 1)
2.7
5.5
V
Digital supply voltage, DVDD (see Note 1)
2.7
5.5
V
NOTE 1: Abs (AVDD – DVDD) < 0.5 V
analog inputs
MIN
Analog input voltage, AIN
Reference input voltage,
voltage REF
TYP
AGND
MAX
UNIT
V
DVDD = 3.3 V to 2.7 V
55% AVDD
VREF
AVDD
DVDD = 5.5 V to 4.5 V
60% AVDD
AVDD
V
digital inputs
MIN
High-level input voltage, VIH
DVDD = 2.7 V to 5.5 V
Low-level input voltage, VIL
DVDD = 2.7 V to 5.5 V
Input SCLK frequency
SCLK pulse duration
duration, clock high
high, tw(SCLKH)
(SCLKH)
SCLK pulse duration,
duration clock low,
low tw(SCLKL)
(SCLKL)
TYP
MAX
2.1
V
0.8
DVDD = 5.5 V to 4.5 V
20
DVDD = 3.6 V to 2.7 V
1
DVDD = 5.5 V to 4.5 V
23
DVDD = 3.6 V to 2.7 V
46
DVDD = 5.5 V to 4.5 V
23
DVDD = 3.6 V to 2.7 V
46
UNIT
10
V
MHz
ns
ns
I/O and control rise time, SCLK, FS, CS, SDIN
4
ns
I/O and control fall time, SCLK, FS, CS, SDIN
4
ns
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
electrical characteristics,over recommended operating free-air temperature range, supply
voltages, and reference voltages (unless otherwise noted)
digital specifications (SDOUT at 25 pF)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Logic inputs
IIH
IIL
High-level input current
DVDD = 5 V,
VI = 5 V
1
µA
Low-level input current
DVDD = 5 V,
VI = 0 V
–1
µA
CI
Input capacitance
Control inputs
15
pF
5
Logic outputs
VOH
VOL
High-level output voltage
IOZH
IOZL
High-impedance-state output current
CO
Output capacitance
IOH = 50 µA – 0.5 mA
IOL = 50 µA – 0.5 mA
Low-level output voltage
DVDD–0.4
V
Low-impedance-state output current
0.4
V
1
µA
–1
µA
5
pF
dc specifications
PARAMETER
TEST CONDITIONS
MIN
Resolution
TYP
MAX
10
UNIT
Bits
Accuracy
Integral nonlinearity, INL
± 0.6
Best fit
LSB
± 0.65
±1
Offset error
± 0.1
± 0.15
%FSR
Gain error
± 0.1
± 0.2
%FSR
15
20
pF
±1
µA
265
780
Ω
Differential nonlinearity, DNL
EO
EG
±1
LSB
Analog input
Ci
Input capacitance
Ilkg
Input leakage current
Ri(MUX)
Input MUX ON resistance
Ri(ADC)
Input MUX ON resistance
VAIN = 0 V to AVDD
DVDD = 3 V,
AVDD = 3 V
DVDD = 5 V,
DVDD = 3 V,
AVDD = 5 V
AVDD = 3 V
235
450
Ω
158
465
Ω
DVDD = 5 V,
AVDD = 5 V
140
268
Ω
Voltage reference
REF
Internal reference voltage
Internal reference mode, VDD = 3 V
2.08
2.26
2.48
V
Internal reference mode, VDD = 5 V
3.48
3.82
4.15
V
Temperature coefficient
100
ri
Input resistance
External reference mode
Ci(VR)
Input capacitance
External reference mode
12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
ppm/°C
kΩ
300
pF
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
electrical characteristics, over recommended operating free-air temperature range, supply
voltages, and reference voltages (unless otherwise noted) (continued)
dc specifications (continued)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Power supply
IDD + IREF
Operating supply current
PD
Power dissi
dissipation
ation
AVDD = 2.7 V,
AVDD = 5.5 V,
DVDD = 2.7 V, fSCLK = 10 MHz†
DVDD = 5.5 V, fSCLK = 20 MHz‡
AVDD = 2.7 V,
AVDD = 5.5 V,
3
5
mA
7.2
8.5
mA
DVDD = 2.7 V
8
13
mW
DVDD = 5.5 V
40
47
mW
CS = AVDD
3
10
CS = AGND
500
AVDD = 2.7
27V
Software
Supply
y current in
power down
IDD + IREF
AVDD = 5.5
55V
Auto
IDD + IREF
CS = AVDD
3
CS = AGND
2000
10
µA
µA
AVDD = 2.7V
175
275
µA
AVDD = 5.5V
200
300
µA
MIN
TYP
MAX
UNIT
External reference
58
61
Internal reference
53
56
External reference
56
61
Internal reference
53
55
† IREF = 0.7 mA typ.
‡ IREF = 1.5 mA typ.
ac specifications
PARAMETER
TEST CONDITIONS
fi = 100 kHz,,
70% of FS
SNR
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
Signal-to-noise
g
ratio
fi = 50 kHz,,
90% of FS
fs = 1
1.25
25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
fi = 100 kHz,,
70% of FS
SINAD
25 MSPS,
MSPS AVDD = 5 V
fs = 1
1.25
fs = 625 KSPS,
KSPS AVDD = 3 V
Signal-to-noise
g
ratio + distortion
fi = 50 kHz,,
90% of FS
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
fi = 100 kHz,,
70% of FS
THD
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
Total harmonic
distortion
fi = 50 kHz
90% of FS
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
POST OFFICE BOX 655303
External reference
61
Internal reference
56
External reference
61
Internal reference
55
External reference
55
58
Internal reference
53
55
External reference
53
58
Internal reference
52
54
dB
dB
External reference
59
Internal reference
55
External reference
60
Internal reference
55
External reference
–60
–55
Internal reference
–70
–58
External reference
–60
–55
Internal reference
–66
–58
External reference
–64
Internal reference
–72
External reference
–63
Internal reference
–68
• DALLAS, TEXAS 75265
dB
13
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
ac specifications (continued)
PARAMETER
TEST CONDITIONS
fi = 100 kHz,,
70% of FS
SFDR
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
Spurious-free
dynamic range
fi = 50 kHz,,
90% of FS
fs = 1.25
1 25 MSPS,
MSPS AVDD = 5 V
fs = 625 KSPS
KSPS, AVDD = 3 V
fi = 100 kHz,,
70% of FS
ENOB
1 25 MSPS,
MSPS AVDD = 5 V
fs = 1.25
fs = 625 KSPS
KSPS, AVDD = 3 V
Effective number of bits
fi = 50 kHz,,
90% of FS
1 25 MSPS,
MSPS AVDD = 5 V
fs = 1.25
fs = 625 KSPS
KSPS, AVDD = 3 V
MIN
TYP
MAX
External reference
–63
–57
Internal reference
–73
–59
External reference
–61
–57
Internal reference
–68
–60
External reference
–66
Internal reference
–75
External reference
–65
Internal reference
–70
External reference
8.8
9.3
Internal reference
8.6
8.9
External reference
8.6
9.3
Internal reference
8.4
8.8
External reference
9.5
Internal reference
8.9
External reference
9.5
Internal reference
8.9
UNIT
dB
dB
Analog Input
Channel-tochannel crosstalk
– 75
BW
Full-power
bandwidth
–1 dB full-scale input sine wave
BW
Small-signal
g
bandwidth
–1 dB
fs
14
Sampling rate
12
–3 dB full-scale input sine wave
15
dB
15
MHz
25
MHz
20
MHz
35
–3 dB
AVDD = 5 V
AVDD = 3 V
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
MHz
0.0625
1.25
0.0625
0.625
MSPS
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
timing requirements†
PARAMETER
TEST CONDITIONS
MIN
DVDD = 5.5 V to 4.5 V
50
DVDD = 3.6 V to 2.7 V
100
TYP
MAX
UNIT
ns
tc(SCLK)
(SCLK)
SCLK cycle time
tw1
Pulse duration, chip select
ts
Sampling period
tconv
Conversion period
ts1
th1
Setup time, FS to SCLK falling edge in DSP mode
5
ns
Hold time, FS to SCLK falling edge in DSP mode
2
ns
ts2
th2
Setup time, FS to CS falling edge in DSP mode
5.5
ns
Hold time, FS to CS falling edge in DSP mode
9
ns
td1
td2
Delay time, FS falling edge to next SCLK falling edge in DSP mode
6
ns
Delay time, SCLK rising edge after CS falling edge in µC mode
4
td3
Delay time, output after SCLK rising edge in µC mode and DSP
mode
ts3
th3
Setup time, serial input data to SCLK falling edge
10
ns
Hold time, serial input data to SCLK falling edge
4
ns
100
tr
Rise time
† Specifications subject to change without notice.
• DALLAS, TEXAS 75265
6
SLCK
cycles
10
SLCK
cycles
ns
10
3
POST OFFICE BOX 655303
ns
20
200
ns
ns
15
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
PARAMETER MEASUREMENT INFORMATION
tc(SCLK)
1
2
3
SCLK
tw1
CS
ts1
th1
td1
FS
ts2
ts3
th2
th3
DI15
SDIN
DI14
DI13
MSB
td3
0
SDOUT
0
Figure 7. DSP Mode Timing Diagrams
td2
1
2
3
4
SCLK
tw1
CS
FS
ts3
SDIN
DI15
th3
DI14
DI13
DI12
MSB
td3
SDOUT
0
0
Figure 8. µC Mode Timing Diagrams
16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
0
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
ANALOG MUX INPUT RESISTANCE
vs
FREE-AIR TEMPERATURE
TOTAL SUPPLY CURRENT
vs
FREE-AIR TEMPERATURE
350
8
AVDD = 5.5 V
AVDD = 2.7 V, AIN = 2 V
6
I CC – Supply Current – mA
Analog Mux Input Resistance
300
250
AVDD = 5.5 V, AIN = 3.8 V
200
150
100
AVDD = 2.7 V
4
2
50
0
–45
0
–45
90
25
TA – Free-Air Temperature – °C
90
Figure 10
Figure 9
SUPPLY CURRENT
vs
CLOCK FREQUENCY (SCLK)
GAIN
vs
INPUT FREQUENCY
8
1
7
VDD = 5.5 V
0
6
–1
5
4
Gain – dB
ICC – Supply Current – mA
25
TA – Free-Air Temperature – °C
VDD = 2.7 V
VDD = 5 V, AIN = 90% of FS,
REF = 5 V, TA = 25°C
––2
3
–3
2
–4
1
0
2.5
–5
5
6.2
7.5
10
12.5
15.4
18
20
0
1
10
100
f – Frequency – MHz
f – Frequency – MHz
Figure 11
Figure 12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
17
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 2.7 V, Internal REF = 2.3 V,
SCLK = 10 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
511
1023
Samples
Figure 13
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
0.8
VCC = 2.7 V, Internal REF = 2.3 V,
SCLK = 10 MHz,
TA = 25°C
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
511
Samples
Figure 14
18
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1023
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 2.7 V, External REF = 2.7 V,
SCLK = 10 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
511
1023
Samples
Figure 15
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 2.7 V, External REF = 2.7 V,
SCLK = 10 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
511
1023
Samples
Figure 16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
19
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
0.8
0.6
VCC = 5.5 V, Internal REF = 3.8 V,
SCLK = 20 MHz,
TA = 25°C
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
1023
511
Samples
Figure 17
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 5.5 V, Internal REF = 3.8 V,
SCLK = 20 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
0
511
Samples
Figure 18
20
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1023
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
0.8
0.6
VCC = 5.5 V, External REF = 5.5 V,
SCLK = 20 MHz,
TA = 25°C
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
511
1023
Samples
Figure 19
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 5.5 V, External REF = 5.5 V,
SCLK = 20 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
511
0
1023
Samples
Figure 20
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
21
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
DNL – Differential Nonlinearity – LSB
DIFFERENTIAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
0.8
0.6
VCC = 5.5 V, External REF = 3.3 V,
SCLK = 20 MHz,
TA = 25°C
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
0
1023
511
Samples
Figure 21
INL – Integral Nonlinearity – LSB
INTEGRAL NONLINEARITY ERROR
vs
DIGITAL OUTPUT CODE
1
VCC = 5.5 V, External REF = 3.3 V,
SCLK = 20 MHz,
TA = 25°C
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
0
511
Samples
Figure 22
22
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1023
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
EFFECTIVE NUMBER OF BITS
vs
INPUT FREQUENCY
EFFECTIVE NUMBER OF BITS
vs
INPUT FREQUENCY
12
AVDD = DVDD = 3 V,
External REF = 3 V
ENOB – Effective Number of Bits – BITS
ENOB – Effective Number of Bits – BITS
12
10
8
6
4
2
AVDD = DVDD = 5 V,
External REF = 5 V
10
8
6
4
2
0
0
0
50
100
150
200
250
0
300
100
300
400
f – Frequency – kHz
Figure 23
Figure 24
EFFECTIVE NUMBER OF BITS
vs
INPUT FREQUENCY
10
10
9
9
8
7
6
5
4
3
2
AVDD = DVDD = 3 V,
Internal REF = 2.3 V
1
500
600
EFFECTIVE NUMBER OF BITS
vs
INPUT FREQUENCY
ENOB – Effective Number of Bits – BITS
ENOB – Effective Number of Bits – BITS
200
f – Frequency – kHz
0
8
7
6
5
4
3
2
AVDD = DVDD = 5 V,
Internal REF = 3.8 V
1
0
0
50
100
150
200
250
300
0
100
f – Frequency – kHz
200
300
400
500
600
f – Frequency – kHz
Figure 25
Figure 26
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
23
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
FFT – Fast Fourier Transform – dB
FAST FOURIER TRANSFORM
vs
FREQUENCY
AIN = 200 kHz,
SCLK = 20 MHz,
AVDD = DVDD = 3 V,
Internal REF = 2.3 V
0
–20
–40
–60
–80
–100
–120
0
100
200
300
400
500
600
500
600
Frequency – KHz
Figure 27
FFT – Fast Fourier Transform – dB
FAST FOURIER TRANSFORM
vs
FREQUENCY
AIN = 200 kHz,
SCLK = 20 MHz,
AVDD = DVDD = 5 V,
Internal REF = 3.8 V
0
–20
–40
–60
–80
–100
–120
0
100
200
300
400
Frequency – KHz
Figure 28
24
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
TYPICAL CHARACTERISTICS
FFT – Fast Fourier Transform – dB
FAST FOURIER TRANSFORM
vs
FREQUENCY
AIN = 200 kHz,
SCLK = 20 MHz,
AVDD = DVDD = External REF = 3 V
0
–20
–40
–60
–80
–100
–120
0
100
200
300
400
500
600
Frequency – KHz
Figure 29
FFT – Fast Fourier Transform – dB
FAST FOURIER TRANSFORM
vs
FREQUENCY
AIN = 200 kHz,
SCLK = 20 MHz,
AVDD = DVDD = External REF = 5 V
0
–20
–40
–60
–80
–100
–120
0
100
200
300
400
500
600
Frequency – KHz
Figure 30
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
25
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
0
0
0
0
DO9 DO8 DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
0
0
0
0
0
SDOUT
SDIN
FS
CS
SCLK
0
Previous Conversion Output
DI5
DI4
1
2
3
ts
4
5
6
DI15 DI14 DI13 DI12 DI11 DI10
7
DI9
8
DI8
9
DI7
DI6
Configure
12
10
11
t conv
13
DI3
14
DI2
15
DI1
16
DI0
1
2
3
4
5
DI15 DI14 DI13 DI12 DI11
0
TYPICAL CHARACTERISTICS
Figure 31. Typical Timing Diagram for DSP Application
26
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLV1570
2.7 V TO 5.5 V 8-CHANNEL 10-BIT 1.25-MSPS
SERIAL ANALOG-TO-DIGITAL CONVERTER
SLAS169A – DECEMBER 1997– REVISED SEPTEMBER 1998
0
0
0
0
0
DO0
DO1
D02
D03
D04
DO5
DO6
DO7
DO8
DO9
0
0
0
0
0
0
SDOUT
Previous Conversion Output
DI4
SDIN
FS
CS
SCLK
1
2
3
ts
4
5
6
DI15 DI14 DI13 DI12 DI11 DI10
7
DI9
8
DI8
DI7
Configure
DI6
DI5
12
11
9
10
t conv
13
DI3
14
DI2
15
DI1
16
DI1
1
DI15
2
DI14
3
DI13
4
DI12
5
DI11
TYPICAL CHARACTERISTICS
Figure 32. Typical Timing Diagram for µC Application
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
27
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright  1998, Texas Instruments Incorporated