Electrical characteristics (continued) – Rainbow Electronics MAX3795 User Manual

Page 4

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MAX3795

1Gbps to 4.25Gbps Multirate VCSEL Driver
with Diagnostic Monitors

4

_______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V

CC

= +2.97V to +3.63V, T

A

= -40

°C to +85°C. Typical values are at V

CC

= +3.3V, TC1 and TC2 are shorted, PEAKSET open, T

A

=

+25

°C, unless otherwise noted.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

- 40°C to + 85° C

8.4

15.6

Deterministic Jitter

DJ

5m A

≤ I

M OD

≤ 15m A,

4.25G b p s, K28.5 ( N otes 2, 5) +100°C

12.7

ps

P-P

APC closed loop

0.5

Random Jitter

RJ

APC open loop (Note 2)

0.5

0.9

ps

RMS

SAFETY FEATURES (see the Typical Operating Characteristics)

High-Current Fault Threshold

V

BMTH

V

BIASMON

> V

BMTH

causes a fault

0.7

0.8

0.9

V

V

BIAS

Fault Threshold

V

BTH

V

BIAS

referenced to V

CC

-0.250

-0.2

-0.150

V

Power-Monitor Fault Threshold

V

PMTH

V

PWRMON

> V

PMTH

causes a fault

0.7

0.8

0.9

V

TX Disable Time

t_

OFF

Time from rising edge of TX_DISABLE to
I

BIAS

= I

BIAS_OFF

and I

MOD

= I

MOD_OFF

(Note 2)

1.8

5

µs

TX Disable Negate Time

t_

ON

Time from rising edge of TX_DISABLE to
I

BIAS

and I

MOD

at 99% of steady state

(Note 2)

55

500

µs

Fault Reset Time

t_

INIT

1

Time to set V

FAULT

= low after power-on or

after rising edge of TX_DISABLE (Note 2)

60

200

ms

Power-On Time

t_

INIT

2

Time after power-on to transmitter-on with
TX_DISABLE low (Note 2)

60

200

ms

Fault Assert Time

t_

FAULT

Time from fault occurrence to V

FAULT

=

high; C

FAULT

< 20pF, R

FAULT

= 4.7k

(Note 2)

1.4

50

µs

Fault Delay Time

t_

FLTDLY

Time from fault to I

BIAS

= I

BIAS_OFF

and

I

MOD

= I

MOD_OFF

; measured with a

continuously occurring fault (Note 2)

1

5

µs

TX_DISABLE Reset

t_

RESET

Time TX_DISABLE must be held high to
reset FAULT (Note 2)

1

µs

Note 1: Supply current measurements exclude I

BIAS

from the total current.

Note 2: AC characteristics guaranteed by design and characterization.
Note 3: Measured by applying a pattern that contains 20µs of K28.5, followed by 5µs of zeros, then 20µs of K28.5, followed by 5µs

of ones. Data rate is equal to 2.5Gbps, with inputs filtered using 1.8GHz Bessel filters.

Note 4: Variation of bias monitor gain for any single part over the range of V

CC

, temperature, 3mA < I

BIAS

< 15mA.

Note 5: Deterministic jitter measured at 4.25Gbps with a K28.5 pattern (00111110101100000101).

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