TSM1285
A 300ksps, Single-supply, Low-Power 12-Bit Serial-output ADC
FEATURES
Alternate Source for MAX1285 and higher-speed
upgrade to MAX1240 and MAX1241
Single-Supply Operation: +2.7V to +3.6V
DNL & INL: ±1LSB (max)
300ksps Sampling Rate
Low Conversion-Mode Supply Current:
2.5mA @ 300ksps
Low Supply Current in Shutdown: 2µA
Internal Track-and-Hold
Internal +2.5V Reference
SPI
®
/QSPI™/MICROWIRE™ 3-Wire Serial-
Interface
1
8-Pin SOIC Package
DESCRIPTION
The TSM1285 – a single-supply, single-channel, 12-
bit analog-to-digital converter (ADC) - is an alternate
source for the MAX1285 and a higher-speed upgrade
to the MAX1240 and MAX1240 ADCs. The TSM1285
combines a high-bandwidth track-and-hold (T/H), a
high-speed serial digital interface, an internal +2.5V
reference, and low conversion-mode power
consumption. The TSM1285 operates from a single
+2.7V to+3.6V supply and draws less than 2.5mA at
300ksps.
Connecting directly to any SPI, QSPI, MICROWIRE™
microcontrollers and other interface-compatible
computing devices, the TSM1285’s 3-wire serial
interface is easy to use and doesn’t require separate,
external logic. An external serial-interface clock
controls the TSM1285’s conversion process and its
output shift register operation.
In PCB-space-conscious, low-power remote-sensor
and data-acquisition applications, the TSM1285 is an
excellent choice for its low-power, ease-of-use, and
small-package-footprint attributes.
The TSM1285BC is fully specified over the
0°C to +70°C temperature range. TSM1285BE is fully
specified over the -40°C to +85°C temperature range.
Both products are available in a 8-pin SOIC package.
APPLICATIONS
Process Control and Factory Automation
Data and Low-frequency Signal Acquisition
Portable Data Logging
Pen Digitizers & Tablet Computers
Medical Instrumentation
Battery-powered Instruments
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National
Semiconductor Corporation.
1
FUNCTIONAL BLOCK DIAGRAM
Page 1
© 2014 Silicon Laboratories, Inc. All rights reserved.
TSM1285
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND.................................................................... -0.3V to +6V
AIN to GND ...................................................... -0.3V to (V
DD
+ 0.3V)
REF to GND ..................................................... -0.3V to (V
DD
+ 0.3V)
Digital Inputs to GND ....................................... -0.3V to (V
DD
+ 0.3V)
DOUT to GND .................................................. -0.3V to (V
DD
+ 0.3V)
DOUT Current ........................................................................ ±25mA
Continuous Power Dissipation (T
A
= +70°C):
8-Pin SOIC (Derate 5.88mW/°C above +70°C) .............. 471mW
Operating Temperature Ranges:
TSM1285BC ...........................................................0°C to +70°C
TSM1285BE ....................................................... -40°C to +85°C
Storage Temperature Range .................................. -60°C to +150°C
Lead Temperature (Soldering, 10s)....................................... +300°C
Soldering Temperature (Reflow) ........................................... +260°C
Electrical and thermal 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 condition beyond those indicated in the operational sections
of the specifications is not implied. Exposure to any absolute maximum rating conditions for extended periods may affect device reliability and
lifetime.
PACKAGE/ORDERING INFORMATION
ORDER NUMBER PART MARKING
TEMPERATURE
CARRIER QUANTITY
RANGE
TSM1285BCSA+
T1285B
TSM1285BCSA+T
TSM1285BESA+
T1285BE
TSM1285BESA+T
Lead-free Program:
Silicon Labs supplies only lead-free packaging.
Tube
0ºC to 70ºC
Tape
& Reel
Tube
-40ºC to +85ºC
Tape
& Reel
97
2500
97
2500
Consult Silicon Labs for products specified with wider operating temperature ranges.
Page 2
TSM1285 Rev. 1.0
TSM1285
ELECTRICAL SPECIFICATIONS
V
DD
= +2.7V to +3.6V; f
SCLK
= 4.8MHz, 50% duty cycle, 16 clocks/conversion cycle, 300ksps; 4.7μF capacitor at
REF; T
A
= -40ºC to +85ºC, unless otherwise noted. Typical values apply at T
A
= +25°C.
PARAMETER
DC ACCURACY
(See Note 1)
Resolution
Relative Accuracy
Differential Nonlinearity
Offset Error
Gain Error
Gain-Error Temperature Coefficient
SYMBOL
CONDITIONS
MIN
12
INL
DNL
ZE
GE
TCGE
See Note 2
No missing codes over temperature
See Note 3
±1.6
70
-80
80
76
3
250
3.3
625
10
< 50
0.5
40
0
10
2.48
2.50
15
±15
0.1
2.52
4.8
60
2.5
±1.0
±1.0
±6.0
±6.0
TYP
MAX
UNITS
Bits
LSB
LSB
LSB
LSB
ppm/°C
dB
dB
dB
dB
MHz
kHz
μs
ns
ns
ps
MHz
%
V
pF
V
mA
ppm/°C
mV/mA
μF
V
V
V
μA
pF
V
V
μA
pF
V
mA
μA
mV
DYNAMIC SPECIFICATIONS
(f
IN
= 75kHz sine wave, 2.5V
PP
, f
SAMPLE
= 300ksps, f
SCLK
= 4.8MHz)
Signal-to-Noise
SINAD
Plus Distortion Ratio
Total Harmonic Distortion
THD
Including the 5th harmonic
Spurious-Free Dynamic Range
SFDR
Intermodulation Distortion
IMD
f
A
= 73kHz, f
B
= 77kHz
Full-Power Bandwidth
FPBW
-3dB point
Full-Linear Bandwidth
FLBW
SINAD > 68dB
CONVERSION RATE
Conversion Time
t
CONV
See Note 4
Track/Hold Acquisition Time
t
ACQ
Aperture Delay
t
AD
Aperture Jitter
t
AJ
Serial Clock Frequency
t
SCLK
Duty Cycle
ANALOG INPUT (AIN)
Input Voltage Range
V
IN
Input Capacitance
C
INA
INTERNAL REFERENCE
REF Output Voltage
VREF
REF Short-Circuit Current
T
A
= +25°C
REF Output Tempco
TCVREF
Load Regulation
See Note 5; 0 to 0.75mA output load
Capacitive Bypass at REF
DIGITAL INPUTS (SCLK, CS, SHDN)
Input High Voltage
V
INH
Input Low Voltage
V
INL
Input Hysteresis
V
HYST
Input Leakage
I
IN
V
INL
= 0V or V
INH
= V
DD
Input Capacitance
C
IND
DIGITAL OUTPUT (DOUT)
Output Voltage Low
V
OL
I
SINK
= 5mA
Output Voltage High
V
OH
I
SOURCE
= 0.5mA
Three-State Leakage Current
I
L
V
CS
= +3V
Three-State Output Capacitance
C
OUT
V
CS
= +3V
POWER SUPPLY
Positive Supply Voltage
V
DD
See Note 6
Positive Supply Current
I
DD
See Note 7; V
DD
= +3.6V
Shutdown Supply Current
I
SHDN
SCLK = V
DD
, SHDN = GND
Power-Supply Rejection
PSR
V
DD
= +2.7V to 3.6V, midscale input
4.7
2.0
2.0
10
0.8
0.2
±1
15
0.4
V
DD
- 0.5
±10
15
2.7
2.5
2
±0.5
3.6
3.5
10
TSM1285 Rev. 1.0
Page 3
TSM1285
TIMING SPECIFICATIONS
V
DD
= +2.7V to +3.6V, T
A
= -40ºC to +85ºC, unless otherwise noted.
PARAMETER
SCLK Period
SCLK Pulse-Width High
SCLK Pulse-Width Low
CS Fall to SCLK Rise Setup
SCLK Rise to CS Rise Hold
SCLK Rise to CS Fall Ignore
CS Rise to SCLK Rise Ignore
SCLK Rise to DOUT Hold
SCLK Rise to DOUT Valid
CS Rise to DOUT Disable
CS Fall to DOUT Enable
CS Pulse-Width High
SYMBOL
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
CSO
t
CS1
t
DOH
t
DOV
t
DOD
t
DOE
t
CSW
CONDITIONS
MIN
208
83
83
45
0
45
45
13
13
100
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF; Refer to Figure 2
C
LOAD
= 20pF; Refer to Figure 1
100
85
85
Note 1:
Tested at V
DD
= V
DD(MIN)
.
Note 2:
Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range has been
calibrated.
Note 3:
Internal reference, offset, and reference errors nulled.
Note 4:
Conversion time is defined as the number of clock cycles multiplied by the clock period; clock has 50% duty cycle.
Note 5:
External load should not change during conversion for specified accuracy. Guaranteed specification limit of 2mV/mA because of
production test limitations.
Note 6:
Electrical characteristics are guaranteed from V
DD(MIN)
to V
DD(MAX)
. For operations beyond this range, see Typical Operating
Characteristics.
Note 7:
TSM1285 tested with 20pF on DOUT and f
SCLK
= 4.8MHz, 0 to 3V. DOUT = full scale.
Page 4
TSM1285 Rev. 1.0
TSM1285
TYPICAL PERFORMANCE CHARACTERISTICS
V
DD
= +3V; f
SCLK
= 4.8MHz; C
LOAD
= 20pF; 4.7μF capacitor at REF; T
A
= 25ºC, unless otherwise noted.
Integral Nonlinearity
0.4
0.3
0.2
DNL - LSB
INL - LSB
0.1
0
-0.1
-0.2
-0.3
-0.4
0
1k
2k
3k
4k
5k
0.25
0.2
0.15
0.2
0.05
0
-0.05
-0.1
-0.15
-0.2
-0.25
0
1k
2k
3k
4k
5k
Differential Nonlinearity
DIGITAL OUTPUT CODE
Offset Error vs Supply Voltage
-0.2
-0.4
OFFSET ERROR - LSB
-0.6
-0.8
-1
-1.2
-1.4
-1.6
-1.8
2.7
2.88
3.06
3.24
3.42
3.6
OFFSET ERROR - LSB
1
0.5
0
-0.5
-1
-1.5
-2
-40
DIGITAL OUTPUT CODE
Offset Error vs Temperature
-15
10
35
60
85
POWER SUPPLY VOLTAGE - Volt
TEMPERATURE - ºC
Gain Error vs Temperature
1.2
1
GAIN ERROR - LSB
0.8
0.6
0.4
0.2
0
-0.2
Gain Error vs Supply Voltage
1.2
1
GAIN ERROR - LSB
0.8
0.6
0.4
0.2
0
-0.2
2.7
2.88
3.06
3.24
3.42
3.6
-0.4
-40
-15
10
35
60
85
POWER SUPPLY VOLTAGE - Volt
TEMPERATURE - ºC
TSM1285 Rev. 1.0
Page 5
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