LTC2854/LTC2855

4

285455fc

For more information www.linear.com/LTC2854

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime. High temperatures degrade operating lifetimes.

Operating lifetime is derated at temperatures greater than 105°C.

Note 2: All currents into device pins are positive; all currents out of device

pins are negative. All voltages are referenced to device ground unless

otherwise specified.

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C, VCC = 3.3V, TE = 0V unless otherwise noted (Note 2).

Note 3: Maximum data rate is guaranteed by other measured parameters

and is not tested directly.

Note 4: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions.

Overtemperature protection activates at a junction temperature exceeding

150°C. Continuous operation above the specified maximum operating

junction temperature may result in device degradation or failure.

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C, VCC = 3.3V, TE = 0V unless otherwise noted (Note 2).

ELECTRICAL CHARACTERISTICS

SWITCHING CHARACTERISTICS

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Driver

fMAX

Maximum Data Rate

Note 3

l

20

Mbps

tPLHD, tPHLD

Driver Input to Output

RDIFF = 54Ω, CL = 100pF (Figure 4)

l

10

50

ns

DtPD

Driver Input to Output Difference

|tPLHD-tPHLD|

RDIFF = 54Ω, CL = 100pF (Figure 4)

l

1

6

ns

tSKEWD

Driver Output Y to Output Z

RDIFF = 54Ω, CL = 100pF (Figure 4)

l

1

±6

ns

tRD, tFD

Driver Rise or Fall Time

RDIFF = 54Ω, CL = 100pF (Figure 4)

l

4

12.5

ns

tZLD, tZHD, tLZD, tHZD Driver Enable or Disable Time

RL = 500Ω, CL = 50pF, RE = 0 (Figure 5)

l

70

ns

tZHSD, tZLSD

Driver Enable from Shutdown

RL = 500Ω, CL = 50pF, RE = VCC (Figure 5)

l

8

µs

tSHDN

Time to Shutdown

RL = 500Ω, CL = 50pF

(DE = ↓, RE = VCC) or (DE = 0, RE ↑)

(Figure 5)

l

100

ns

Receiver

tPLHR, tPHLR

Receiver Input to Output

CL = 15pF, VCM = 1.5V, |VAB| = 1.5V, tR and

tF < 4ns (Figure 6)

l

50

70

ns

tSKEWR

Differential Receiver Skew

|tPLHR-tPHLR|

CL = 15pF (Figure 6)

l

1

6

ns

tRR, tFR

Receiver Output Rise or Fall Time

CL = 15pF (Figure 6)

l

3

12.5

ns

tZLR, tZHR, tLZR, tHZR Receiver Enable/Disable

RL = 1k, CL =15pF, DE = VCC (Figure 7)

l

50

ns

tZHSR, tZLSR

Receiver Enable from Shutdown

RL = 1k, CL = 15pF, DE = 0V (Figure 7)

l

8

µs

tRTEN, tRTZ

Termination Enable or Disable Time

VB = 0V, VAB = 2V, RE = VCC, DE = 0V

(Figure 8)

l

100

µs

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

ICCT

Supply Current in Transmit Mode

No Load, DE = VCC, RE = VCC, TE = 0V

l

450

1000

µA

ICCTR

Supply Current with Both Driver and

Receiver Enabled

No Load, DE = VCC, RE = 0V, TE = 0V

l

450

1000

µA

ICCTERM

Supply Current in Termination Mode

DE = 0V, RE = VCC, TE = VCC

l

110

180

µA

ICCTERMR

Supply Current in Receive and

Termination Mode

DE = 0V, RE = 0V, TE = VCC

l

450

950

µA

ICCTERMT

Supply Current in Transmit and

Termination Mode

DE = VCC, RE = VCC, TE = VCC

l

470

1000

µA

ICCTERMTR

Supply Current with Driver, Receiver

and Termination Enabled

DE = VCC, RE = 0V, TE = VCC

l

470

1000

µA

ESD Protection

ESD Protection for RS485/RS422 Pins

A, B on LTC2854, Human Body Model

Y, Z, A, B on LTC2855, Human Body Model

±25

±15

kV

kV