LTM2893/LTM2893-1
100MHz Isolated ADC
Serial Inter face
FEATURES DESCRIPTION
n
Isolated Interface: 6000V for 1 Minute The LTM 2893 is a high speed isolated Module
RMS
n
CSA (IEC/UL) Approved, File #255632 (micromodule) SPI interface with ADC control signals. The
n
LTM2893 is optimized for isolating 1Msps high resolution
100MHz SPI-Compatible I/O
n
18-bit SAR ADCs, such as the LTC2338 and similar families,
Configurable SPI Word Length 8 to 32 Bits
n
and can interface with most general purpose ADCs. The
Low Jitter Conversion Start (30ps )
RMS
n
LTM2893-1 is optimized for isolating the LTC2348 and
Supports Simultaneously Sampled ADCs
n similar families of simultaneous sampling ADCs that require
Read Only (LTM2893), Read/Write (LTM2893-1)
n writing configuration settings into the ADC. LTM2893
Three Isolated Multiplexer Select Signals
n isolates the conversion start, sampling signal, with very
1.71V to 5.5V I/O Voltages
n low aperture jitter (30ps) and low latency (20ns).
3V to 5.5V Supply Voltages
n
High Common Mode Transient Immunity
The interface enables fast throughput with no cycle
n
15mm 6.25mm BGA Package
latency, which makes the LTM2893 ideally suited for a
wide variety of applications. The LTM2893 has a high
speed SPI-compatible serial port that supports 1.71V to
APPLICATIONS
5.5V logic and is configurable for ADCs with 8 to 32 bit SPI
n
Remote Sensing
word lengths. It also isolates three select signals (SA, SB,
n
High Speed Data Acquisition
SC) for controlling analog multiplexers or gain settings.
n
Industrial Process Control
The isolation barrier tolerates large voltage ground
n
Test and Measurement Equipment
variations between the logic interface and the isolated
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side of the LTM2893. Uninterrupted communication is
maintained during voltage transients greater than 50kV/s.
TYPICAL APPLICATION
LTC2328-18 ADC Isolation A = 10.24V, SNR = 95dB
IN
3.3Vi 5Vi
LTC6655-2.048
+15Vi
3.3V V V
IN OUT_F
5V 5Vi 3.3Vi 1F
SHDN V
OUT_S 2.2F
V V V V
L CC CC2 L2
0.1F 10F
LTM2893
500
MASTER
10V
47F +
IN
FPGA
OV V REFIN INPUT
DD DD
CNV CNV2
REFBUF
CNV CNV2 CNV LT1468
OUT
20
BUSY BUSY2
+
BUSY BUSY2 BUSY
IN
IN
SS SS2 6.8nF
SPI
LTC2328-18 3.3nF
SPI
SCK SCK2
INTERFACE SCK
INTERFACE
MISOA MISOA2 IN
SDO
BUFFER
20
INPUT
SA SA2 RDL
VDDLBYP
RETURN
CHAIN
SB SB2 1F
SELECT SELECT2
SC SC2 2.2F
15Vi
28931 TA01a
Rev C
1
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ISOLATION BARRIERLTM2893/LTM2893-1
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Note 1)
TOP VIEW
Supply Voltages
1 2 3 4 5 6
V to GND ................................................ 0.3V to 6V
L
ON SS MOSI SCK BUSY CNV
V to GND .............................................. 0.3V to 6V A
CC
V
L MISOA MISOB CSC GND FAULT
B
V GND GND SA SB SC
Isolated Supply Voltages CC
C
V to GND2 ............................................ 0.3V to 6V
L2
D
V to GND2 .......................................... 0.3V to 6V
CC2
E
Logic Signals
F
ON, CNV, BUSY, SA, SB, SC,
G
SS, CSC, MISOA, MISOB,
H
SCK, MOSI ........................... GND 0.3V to V + 0.3V
L
FAULT ........................................... GND 0.3V to 6.3V J
K
Isolated Signals
L
MISOA2, MISOB2, ON2, BUSY2,
M
BUSYS, MOSI2, CNV2, SCK2, SS2,
V GND2 GND2 SA2 SB2 SC2
CC2
SA2, SB2, SC2 ..................GND2 0.3V to V + 0.3V
N
L2
V V
L2 MISOA2 MISOB2 L2 GND2 BUSYS
P
Operating Temperature Range (Note 11) ON2 SS2 MOSI2 SCK2 BUSY2 CNV2
R
LTM2893C ............................................... 0C to 70C
LTM2893I ............................................40C to 85C
BGA PACKAGE
36-PIN (15mm 6.25mm 2.06mm)
LTM2893H ......................................... 40C to 125C
T = 125C, = 36C/W, = 27.5C/W, = 17.5C/W
JMAX JA JCTOP JCBOTTOM
Storage Temperature Range .............. 55C to 125C
= 19.1C/W, WEIGHT = 0.36g
JB
Maximum Internal Operating Temperature ....... 125C
Peak Solder Reflow Temperature ......................260C
ORDER INFORMATION
PART MARKING
PACKAGE MSL
PART NUMBER TYPE BALL FINISH DEVICE FINISH CODE RATING TEMPERATURE RANGE
LTM2893CY#PBF 0C to 70C
LTM2893IY#PBF BGA SAC305 (RoHS) LTM2893Y e1 3 40C to 85C
LTM2893HY#PBF 40C to 125C
LTM2893CY-1#PBF 0C to 70C
LTM2893IY-1#PBF BGA SAC305 (RoHS) LTM2893Y-1 e1 3 40C to 85C
LTM2893HY-1#PBF 40C to 125C
Device temperature grade is indicated by a label on the shipping container. This product is not recommended for second side reflow.
This product is moisture sensitive. For more information, go to
Pad or ball finish code is per IPC/JEDEC J-STD-609.
Recommended BGA PCB Assembly and Manufacturing Procedures.
BGA Package and Tray Drawings
Rev C
2
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