MAXIM MAX3967 Technical data

MAX3967

270Mbps SFP LED Driver

________________________________________________________________ Maxim Integrated Products 1

TCNOM

1

2

3

4

5

6

7 8 9 101112

13

14

15

16

17

18

192021222324

TC

PB1

PB2

PB3

V

EEOUT

OUT+

OUT+

OUT-

N.C.

V

CCOUT

V

CCOUT

V

CC

N.C.

MON

MODSET

IN-

IN+

V

CC

VEETX_DISABLE

TCMIN

TOP VIEW

THE EXPOSED PAD MUST BE CONNECTED TO GROUND FOR
PROPER THERMAL AND ELECTRICAL PERFORMANCE

MAX3967

V

EEOUT

OUT-

THIN QFN (4mm x 4mm)

Pin Configuration

19-3252; Rev 0; 5/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX3967ETG -40°C to +85°C 24 Thin QFN
MAX3967E/D -40°C to +85°C Dice*

General Description

The MAX3967 is a programmable LED driver for fiber
optic transmitters operating at data rates up to
270Mbps. The circuit contains a high-speed current dri­ver with programmable temperature coefficient (temp­co), adjustments for LED prebias voltage, and a disable
feature. The circuit accepts PECL data inputs, and
operates from a single +2.97V to +5.5V power supply.

The SFP LED driver can switch up to 100mA into typical
high-speed light-emitting diodes. As temperature
increases, the device’s modulation current increases
with a tempco that is programmable from 2500ppm/°C
to 12,000ppm/°C. The modulation current is pro­grammed with a single external resistor.

The MAX3967’s LED prebias voltage is programmable
from 400mV to 925mV. The prebias circuit produces
peaking current, which improves the LED switching
speed.

Complementary current outputs help to maintain a con­stant supply current, reducing EMI and supply noise
generated by the transmitter module. The MAX3967 is
available in die form, or in a 4mm x 4mm, 24-pin thin
QFN package.

Applications

Multimode LED Transmitters
Fast Ethernet/FDDI
155Mbps LAN ATM Transceivers
ESCON Receivers
SFP Transceivers

Features

♦ TX_DISABLE for SFP Compatibility
♦ Single +2.97V to +5.5V Power Supply
♦ Adjustable Temperature Compensation
♦ Adjustable Modulation Current
♦ Complementary Output Reduces Supply Noise
♦ Programmable LED Prebias Voltage
♦ Available in 24-Pin QFN or Die

Typical Operating Circuits appear at end of data sheet.

*Dice are tested and guaranteed only at T

A

= +25°C.

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MAX3967

270Mbps SFP LED Driver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

Supply Voltage at VCC, V

CCOUT

(

V

EE

,

V

EEOUT

= 0V) ..............................................-0.5V to +7V

Current into OUT+, OUT-................................-40mA to +160mA

Differential Output Voltage (OUT+ to OUT-) .........-3.3V to +3.3V

Voltage at PB1, PB2, PB3,

IN+, IN-, OUT+, OUT-, TX_DISABLE......-0.5V to (V

CC

+ 0.5V)

Voltage at TCMIN, TCNOM, TC, MODSET, MON ....-0.5V to +2V

Continuous Power Dissipation (T

A

= +85°C)

24-Lead Thin QFN (derate 20.8mW/C

°

above +85°C).............................................................1354mW

Operating Junction Temperature Range...........-40°C to +150°C

Die Attach Temperature...................................................+400°C

Storage Temperature Range.............................-50°C to +150°C

Lead Temperature (soldering, 10s).................................+300°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

DC ELECTRICAL CHARACTERISTICS

(Load as specified in Figure 1; VCC= +2.97V to +5.5V (at the VCCpins); V

EE, VEEOUT

= 0V; TA= -40°C to +85°C, unless otherwise

noted. Temperature coefficients are referenced to T

A

= +25°C. Typical values are at VCC= +3.3V, TA= +25°C, unless otherwise

noted. Dice are tested at T

A

= +25°C only.)

PARAMETER

CONDITIONS

UNITS

Data Input High Voltage Referenced to VCC, DC-coupled input

V

Data Input Low Voltage Referenced to VCC, DC-coupled input

V

Supply Current I

CC

(Note1) 30 39 mA

Input Current at IN+ or IN- -50 +50 µA

TA = -40°C 110
TA = +25°C 124

R

MODSET

= 698Ω

(Note 2)

T

A

= +85°C 139
TA = -40°C14
TA = +25°C18

R

MODSET

= 3.0kΩ

(Note 3)

T

A

= +85°C22

Modulation Current

(Note 3)

75

mA

PB1, PB2, PB3 = (open, open, open)
PB1, PB2, PB3 = (VEE, VEE, open)

Prebias Voltage

PB1, PB2, PB3 = (V

EE

, VEE, VEE)

V

Maximum tempco (TC open)
Nominal tempco (TC shorted to TCNOM)

Temperature Coefficient of
Modulation Current

Minimum tempco (TC shorted to TCMIN)

ppm/°C

Prebias Resistor

66 78 90 Ω
TX_DISABLE Resistance Resistance to VEE (Note 4) 50 65 100 kΩ
TX_DISABLE High V

IH

2.0 V

TX_DISABLE Low V

IL

0.8 V

Monitor Gain

I

MON

/ I

MODSET

, V

MON

< 1.1V,

R

MODSET

= 1kΩ, TC = TCMIN

1

A/A

Note 1: R

MODSET

= 1kΩ. Excludes I

OUT

+ and I

OUT

-, TX_DISABLE high or low.

Note 2: TC connected to TCMIN.
Note 3: V

CC

=

+3.3V, V

LED

=

1.55V, prebias voltage programmed at 0.625V (nominal), T

A

= +25°C. R

MODSET

= 1kΩ, (programs

approximately 80mA), TC connected to TCNOM.

Note 4: The TX_DISABLE pin is internally pulled low. The driver is enabled when TX_DISABLE is left open.

SYMBOL

MIN TYP MAX

-1.165 -0.880

-1.810 -1.475

66.0

R

PREBIAS

0.368 0.400 0.451

0.575 0.625 0.696

0.848 0.925 1.026
12,000

3600
2500

0.92

84.5

1.08

MAX3967

270Mbps SFP LED Driver

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(Load as specified in Figure 1, unless otherwise noted. VCC= +2.97V to +5.5V (at the VCCpins), R

MODSET

= 1kΩ, TA= -40°C to

+85°C. Input data edge speed = 1ns (typ), PB1 = PB2 = V

EE

, PB3 = open. Typical values are at VCC= +3.3V, TC connected to

TCNOM, T

A

= +25°C.) (Note 5)

PARAMETER

CONDITIONS

UNITS

Data Input Range Differential input

mV

P-P

Output-Current Edge Speed

615

ps

Output-Current Pulse-Width
Correction (PWC)

Note 6 -80 ps
266Mbps (Note 7) 140

Output-Current Data-Dependent
Jitter

DJ

155Mbps (Note 8) 150 250

ps

P-P

Random Jitter RJ 3

ps

RMS

TX_DISABLE Assert Time t_off

Time from rising edge of TX_DISABLE to
output at 10% of steady state

0.5 µs

TX_DISABLE Negate Time t_on

Time from rising edge of TX_DISABLE to
output at 90% of steady state

0.5 µs

Power-On Time t_init

Time from V

CC

> 2.97V to output at 90% of

steady state

0.1 2 ms

Figure 1. MAX3967 Output Test Loads

SWITCHING DIODE

OSCILLOSCOPE

OUT-

L1

OUT+

OUT+

OUT-

AC ELECTRICAL LOADDC ELECTRICAL LOAD

FOR PREBIAS VOLTAGE

DC ELECTRICAL LOAD

(EXCEPT PREBIAS VOLTAGE)

OUT+

OUT-

MAX3967MAX3967MAX3967

V

CC

V

CC

V

LED

1.55V

50Ω

5Ω

50Ω

0.1µF

0.1µF

FERRITE
BEAD

V

CC

V

PREBIAS

Note 5: AC characteristics are guaranteed by design and characterization.
Note 6: PWC = (width

CURRENT ON

- width

CURRENT OFF

) / 2.

Note 7: Test pattern is a K28.5 (0011 1110 1011 0000 0101) transmitted at 266Mbps.
Note 8: Test pattern is equivanlent to a 2

13

- 1 PRBS containing 72 consecutive zeros or 72 consecutive ones.

SYMBOL

20% to 80%, input is a 12.5MHz square wave 300

MIN TYP MAX

500 2400

1230

0.01

0.01

MAX3967

270Mbps SFP LED Driver

4 _______________________________________________________________________________________

Typical Operating Characteristics

(MAX3967ETG in Maxim evaluation board, VCC= +3.3V, PB1 = PB2 = VEE, PB3 = open, TC connected to TCNOM, R

MODSET

= 1kΩ,

TA= +25°C, unless otherwise noted.)

40
38
36
34
32
30
28
26
24
22
20

-40 -20 -10-30 0 10 20 30 40 50 60 70 80 90

SUPPLY CURRENT

vs. TEMPERATURE

MAX3967 toc01

AMBIENT TEMPERATURE (°C)

SUPPLY CURRENT (mA)

EXCLUDES CURRENT INTO OUT+ AND OUT-

VCC = 5.0V

VCC = 3.3V

0

40

20

80

60

100

120

-40 20 40-20 0 60 80

MODULATION CURRENT

vs. TEMPERATURE

MAX3967 toc02

AMBIENT TEMPERATURE (°C)

MODULATION CURRENT (mA)

MINIMUM TEMPCO

NOMINAL TEMPCO

MAXIMUM TEMPCO

0

40

20

80

60

100

120

0608020 40 100 120 140

DIE MODULATION CURRENT

vs. TEMPERATURE

MAX3967 toc03

JUNCTION TEMPERATURE (°C)

MODULATION CURRENT (mA)

MINIMUM TEMPCO

NOMINALTEMPCO

MAXIMUM TEMPCO

100,000

1000

1 10 100

MODULATION CURRENT TEMPCO

vs. R

TC

MAX3967 toc04

RTC (kΩ)

MODULATION CURRENT TEMPCO (ppm/

°

C)

10,000

200

10

500 1k 10k

MODULATION CURRENT

vs. R

MODSET

MAX3967 toc05

R

MODSET

(Ω)

MODULATION CURRENT (mA)

100

MINIMUM TEMPCO

NOMINALTEMPCO

MAXIMUM TEMPCO

200

10

500

1k

8k

DIE MODULATION CURRENT

vs. R

MODSET

MAX3967 toc06

R

MODSET

(Ω)

MODULATION CURRENT (mA)

100

MAXIMUM TEMPCO

NOMINALTEMPCO

MINIMUM TEMPCO

EYE DIAGRAM (ELECTRICAL)

266Mbps

MAX3967 toc07

500ps/div

PATTERN = 2

31

- 1 PRBS

EYE DIAGRAM (OPTICAL)

155Mbps

MAX3967 toc08

1ns/div

RECEIVER BW = 200MHz, VCC = 2.97V, TA = +85°C,
P

AVE

= -17.1dBm, PATTERN = 2

31

- 1 PRBS

EYE DIAGRAM (OPTICAL)

155Mbps

MAX3967 toc09

1ns/div

RECEIVER BW = 200MHz, VCC = 5.5V, TA = -40°C,
P

AVE

= -15.8dBm, PATTERN = 2

31

- 1 PRBS

MAX3967

270Mbps SFP LED Driver

_______________________________________________________________________________________ 5

EYE DIAGRAM (OPTICAL)

155Mbps

MAX3967 toc10

1ns/div

RECEIVER BW = 200MHz, VCC = 5.5V, TA = +85°C,
P

AVE

= -17.1dBm, PATTERN = 2

31

- 1 PRBS

EYE DIAGRAM (OPTICAL)

155Mbps

MAX3967 toc11

1ns/div

RECEIVER BW = 200MHz, VCC = 2.97V, TA = -40°C,
P

AVE

= -15.8dBm, PATTERN = 2

31

- 1 PRBS

0

2

1

4

3

5

6

0 102030405060708090

RANDOM JITTER

vs. TEMPERATURE

MAX3967 toc12

AMBIENT TEMPERATURE (°C)

RANDOM JITTER (ps

RMS

)

VCC = 5.0V
MINIMUM TEMPCO

VCC = 3.3V
MAXIMUM TEMPCO

TX_DISABLE NEGATE TIME

MAX3967 toc13

4ns/div

LED

OUTPUT

TX_DISABLE

t_on

TX_DISABLE ASSERT TIME

MAX3967 toc14

4ns/div

LED

OUTPUT

TX_DISABLE

t_off

Typical Operating Characteristics (continued)

(MAX3967ETG in Maxim evaluation board, VCC= 3.3V, PB1 = PB2 = VEE, PB3 = open, TC connected to TCNOM, R

MODSET

= 1kΩ,

TA= +25°C, unless otherwise noted.)