LTM2883 View Datasheet(PDF) - Linear Technology

Part Name

Description

Manufacturer

LTM2883

SPI/Digital or I2C µModule Isolator with Adjustable ±12.5V and 5V Regulated Power

Linear Technology 

LTM2883

Applications Information

The maximum data rate for bidirectional communication

is 4MHz, based on a synchronous system, as detailed in

the timing waveforms. Slightly higher data rates may be

achieved by skewing the clock duty cycle and minimiz-

ing the SDO to SCK set-up time, however the clock rate

is still dominated by the system propagation delays. A

discussion of the critical timing paths relative to Figure 6

and 7 follows.

• CS to SCK (master sample SDO, 1st SDO valid)

t0 → t1 ≈50ns, CS to CS2 propagation delay

t1 → t1+ Isolated slave device propagation

(response time), asserts SDO2

t1 → t3 ≈50ns, SDO2 to SDO propagation delay

t3 → t5 Set-up time for master SDO to SCK

CPHA = 0

CS = SDOE

CS2

SDI

SDI2

SCK (CPOL = 0)

SCK2 (CPOL = 0)

SCK (CPOL = 1)

SCK2 (CPOL = 1)

SDO

SDO2

INVALID

t0

t1 t2 t3 t4

t5

t6

t7 t9 t10

t8

t11 t12

Figure 6. SPI Timing, Bidirectional, CPHA = 0

CPHA = 1

CS = SDOE

CS2

SDI

SDI2

SCK (CPOL = 0)

SCK2 (CPOL = 0)

SCK (CPOL = 1)

SCK2 (CPOL = 1)

SDO

SDO2

18

INVALID

t0

t1 t2 t3 t4

t5

t6

t7 t9 t10

t8

t11 t12

Figure 7. SPI Timing, Bidirectional, CPHA = 1

t13 t14 t15

t17 t18

2883 F06

t13 t14 t15 t16 t17 t18

2883 F07

2883f

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