B
u
r
r
Ć
B
r
o
w
n
P
r
o
d
u
c
t
s
f
r
o
m
T
e
x
a
s
I
n
s
t
r
u
m
e
n
t
s
ADS7887
ADS7888
SLAS468–JUNE 2005
10-/8-Bit, 1.25-MSPS, MICRO-POWER, MINIATURE
SAR ANALOG-TO-DIGITAL CONVERTERS
FEATURES
APPLICATIONS
•
•
•
Base Band Converters in Radio Communi-
cation
Motor Current/Bus Voltage Sensors in Digital
Drives
Optical Networking (DWDM, MEMS Based
Switching)
•
•
•
•
•
•
•
1.25-MHz Sample Rate Serial Device
10-Bit Resolution – ADS7887
8-Bit Resolution – ADS7888
Zero Latency
25-MHz Serial Interface
Supply Range: 2.35 V to 5.25 V
Typical Power Dissipation at 1.25 MSPS:
– 3.8 mW at 3-V VDD
•
•
•
•
•
Optical Sensors
Battery Powered Systems
Medical Instrumentations
High-Speed Data Acquisition Systems
High-Speed Closed-Loop Systems
– 8 mw at 5-V VDD
•
•
•
•
•
•
•
•
±0.35 LSB INL, DNL – ADS7887
±0.15 LSB INL, ±0.1 LSB DNL – ADS7888
61dB SINAD, -84 dB THD – ADSA7887
49.5 dB SINAD, -67.5 dB THD – ADS7888
Unipolar Input Range: 0 V to VDD
Power Down Current: 1 µA
Wide Input Bandwidth: 15 MHz at 3 dB
6-Pin SOT23 and SC70 Packages
DESCRIPTION
The ADS7887 is a 10-bit, 1.25-MSPS analog-to-digital converter (ADC), and the ADS7888 is a 8-bit, 1.25-MSPS
ADC. The devices include a capacitor based SAR A/D converter with inherent sample and hold. The serial
interface in each device is controlled by the CS and SCLK signals for glueless connections with microprocessors
and DSPs. The input signal is sampled with the falling edge of CS, and SCLK is used for conversion and serial
data output.
The devices operate from a wide supply range from 2.35 V to 5.25 V. The low power consumption of the devices
make them suitable for battery-powered applications. The devices also include a power saving powerdown
feature for when the devices are operated at lower conversion speeds.
The high level of the digital input to the device is not limited to device VDD. This means the digital input can go as
high as 5.25 V when device supply is 2.35 V. This feature is useful when digital signals are coming from other
circuit with different supply levels. Also this relaxes restriction on power up sequencing.
The ADS7887 and ADS7888 are available in 6-pin SOT23 and SC70 packages and are specified for operation
from -40°C to 125°C.
Micro-Power Miniature SAR Converter Family
BIT
12-Bit
< 300 KSPS
ADS7866 (1.2 VDD to 3.6 VDD
ADS7867 (1.2 VDD to 3.6 VDD
ADS7868 (1.2 VDD to 3.6 VDD
300 KSPS – 1.25 MSPS
)
)
)
ADS7886 (2.35 VDD to 5.25 VDD
ADS7887 (2.35 VDD to 5.25 VDD
ADS7888 (2.35 VDD to 5.25 VDD
)
)
)
10-Bit
8-Bit
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.
PRODUCTION DATA information is current as of publication date.
Copyright © 2005, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.