Maxim MAX3665EUA, MAX3665E-D Datasheet

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19-1601; Rev 0; 1/00

________________General Description

The MAX3665 low-power transimpedance preamplifier
for 622Mbps SDH/SONET applications consumes only
70mW at VCC= 3.3V. Operating from a single +3.3V or
+5.0V supply, it converts a small photodiode current to a
measurable differential voltage. A DC cancellation circuit
provides a true differential output swing over a wide
range of input current levels, thus reducing pulse-width
distortion. The differential outputs are back-terminated
with 50Ω per side.

The overall transimpedance gain is nominally 8kΩ. For
input signal levels beyond approximately 50µAp-p, the
amplifier will limit the output swing to 250mV. The
MAX3665’s low 55nA input noise provides a typical
sensitivity of -33.2dBm in 1300nm, 622Mbps receivers.

The MAX3665 is designed to be used in conjunction
with the MAX3676 clock recovery and data retiming IC
with limiting amplifier. Together they form a complete

3.3V or 5.0V 622Mbps SDH/SONET receiver.

In die form, the MAX3665 is designed to fit on a header
with a PIN diode. It includes a filter connection that pro­vides positive bias for the photodiode through a 1.5kΩ
resistor to VCC. The device is available in an 8-pin
µMAX package.

________________________Applications

SDH/SONET Receivers

PIN Photodiode Preamplifiers and Receivers

Regenerators for SDH/SONET

____________________________Features

♦ +3.3V or +5.0V Single-Supply Operation

♦ 55nA

RMS

Input-Referred Noise

♦ 70mW Power Consumption at V

CC

= 3.3V

♦ 8kΩ Gain

♦ 450µA Peak Input Current

♦ 260ps max Deterministic Jitter
♦ Differential Output Drives 100Ω Load

♦ 470MHz Bandwidth

MAX3665

622Mbps, Ultra-Low-Power, 3.3V

Transimpedance Preamplifier for SDH/SONET

________________________________________________________________ Maxim Integrated Products 1

__________________________________________________Typical Application Circuit

PART

MAX3665EUA -40°C to +85°C

TEMP. RANGE PIN-PACKAGE

8 µMAX

EVALUATION KIT

AVAILABLE

_______________Ordering Information

Pin Configuration appears at end of data sheet.

Note: Dice are designed to operate over a -40°C to +140°C

junction temperature (T

j

) range, but are tested and guaranteed

at T

A

= +25°C.

MAX3665E/D (see Note) Dice

C

FILT

FILT

IN

R

1.5k

FILT

3.3V

0.01µF

V

CC

GND

MAX3665

OUT+

OUT-

50Ω

50Ω

0.1µF

0.1µF

3.3V

LIMITING

MAX3676

AMP

CLOCK

AND

DATA

RECOVERY

CLK

DATA

MAX3665

622Mbps, Ultra-Low-Power, 3.3V
Transimpedance Preamplifier for SDH/SONET

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +3.3V ±10% or +5.0V ±10%, 100Ω load between OUT+ and OUT-, TA= -40°C to +85°C. Typical values are at VCC= +3.3V,
T

A

= +25°C, unless otherwise noted.)

AC ELECTRICAL CHARACTERISTICS

(VCC= +3.3V ±10% or +5.0V ±10%, 100Ω load between OUT+ and OUT-, source capacitance = 0.5pF, TA= -40°C to +85°C. Typical
values are at V

CC

= +3.3V, TA= +25°C, unless otherwise noted.) (Notes 1 and 2)

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.

Note 1: AC characteristics are guaranteed by design.
Note 2: Measured with a 3-pole filter at the output. C

IN

= 0.5pF, IIN= 0, C

FILT

= 1000pF.

Note 3: PSRR = -20log (∆V

OUT

/ ∆VCC).

V

CC

........................................................................-0.5V to +6.5V

Continuous Current at IN ....................................................±5mA

Voltage at OUT+, OUT- ...................(V

CC

- 1.5V) to (VCC+ 0.5V)

Voltage at FILT ...........................................-0.5V to (VCC+ 0.5V)

Continuous Power Dissipation (T

A

= +85°C)

8-Pin µMAX (derate 4.5mW/°C above +85°C) ...........295mW

Operating Junction Temperature (die) ..............-55°C to +150°C

Processing Temperature (die) .........................................+400°C

Storage Temperature Range .............................-55°C to +150°C

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

I

IN

= 0

IIN= 0 to 10µAp-p

IIN= 0 to 300µA

IIN= 450µAp-p

Differential output

IIN= 300µA

CONDITIONS

mA

21 30

I

CC

Supply Current

%

±5

V

0.8 0.95

V

IN

Input Bias Voltage

Gain Nonlinearity

kΩ

1.5

R

FILT

Filter Resistor

mVp-p

260 450

V

OUT(MAX)

Maximum Output Voltage

kΩ

78

z

21

Small-Signal Transimpedance

V

VCC- 0.15

Output Common-Mode Voltage

mV

±5

∆V

OUT

Differential Output Offset

Ω

48 50 52

Z

OUT

Output Impedance (per side)

UNITSMIN TYP MAXSYMBOLPARAMETER

-3dB with IIN= 5µA

Relative to gain at 10MHz

2

13

- 1 PRBS with 100 CIDs

CONDITIONS

kHz

20 40

MHz

404 470

BW

-3dB

Small-Signal Bandwidth

Low-Frequency Cutoff

100 260

psJ

D

Deterministic Jitter

UNITSMIN TYP MAXSYMBOLPARAMETER

RMS Noise Referred to Input i

n

55 72

nA

Power-Supply Rejection Ratio PSRR

f < 1MHz, differential referred to output,
∆VCC= 30mVp-p (Note 3)

36 47

dB

MAX3665

622Mbps, Ultra-Low-Power, 3.3V

Transimpedance Preamplifier for SDH/SONET

_______________________________________________________________________________________ 3

__________________________________________Typical Operating Characteristics

(VCC= +3.3V, includes off-chip filter, see Figure 3b, TA= +25°C, unless otherwise noted.)

INPUT-REFERRED NOISE

vs. TEMPERATURE

100

90

80

70

60

50

40

30

RMS NOISE CURRENT (nA)

20

10

0

-40 -20 0 20 40 60 80 100

C

= 1.5pF

IN

C

= 1pF

IN

C

= 0.5pF

IN

CIN IS SOURCE CAPACITANCE PRESENTED TO
DIE. IINCLUDES PACKAGE PARASITIC,
PIN DIODE, AND PARASITIC INTERCONNECT
CAPACITANCE.

JUNCTION TEMPERATURE (°C)

INPUT-REFERRED NOISE

vs. DC INPUT CURRENT

250

SOURCE CAPACITANCE = 0.5pF

200

150

100

RMS NOISE CURRNENT (nA)

50

0

0.1 1 10

DC INPUT CURRENT (µA)

100 1000

MAX3665 TOC01

MAX3665 toc04

SMALL-SIGNAL GAIN

vs. FREQUENCY

79

78

77

76

75

74

GAIN (dB)

73

72

71

70

69

10k 100k 1M 10M 100M 1G

FREQUENCY (Hz)

SMALL-SIGNAL TRANSIMPEDANCE

vs. TEMPERATURE

TRANSIMPEDANCE (Ω)

8100

8000

7900

7800

7700

7600

7500

7400

VCC = 5.0V

VCC = 3.3V

-40 0 20-20 40 60 80 100

AMBIENT TEMPERATURE (°C)

MAX3665 toc02

PWD (ps)

MAX3665 toc05

PWD (ps)

PULSE-WIDTH DISTORTION vs.

TEMPERATURE (INPUT = 100µAp-p)

50

45

40

35

30

25

20

15

VCC = 3.3V

10

5

0

-40 -20 0 20 40 60 80 100
AMBIENT TEMPERATURE (°C)

VCC = 5.0V

PULSE-WIDTH DISTORTION vs.

TEMPERATURE (INPUT = 450µAp-p)

50

45

40

35

30

25

20

15

10

5

0

-40 -20 0 20 40 60 80 100

V

= 3.3V

CC

V

= 5.0V

CC

AMBIENT TEMPERATURE (°C)

MAX3665 toc03

MAX3665 toc06

BANDWIDTH vs. TEMPERATURE

575

V

= 3.3V or 5.0V

CC

550

525

500

475

BANDWIDTH (MHz)

450

425

400

-40 0 20-20 40 60 80 100
AMBIENT TEMPERATURE (°C)

160

140

MAX2665 toc07

120

100

80

60

PEAK-TO-PEAK JITTER (ps)

40

20

0

DATA-DEPENDENT JITTER

vs. INPUT SIGNAL AMPLITUDE

VCC = 3.3V

VCC = 5.0V

0 150 20050 100 250 300 350 400 450

PEAK-TO-PEAK AMPLITUDE (µA)

OUTPUT COMMON-MODE VOLTAGE

(REFERENCED TO V

-0.10

-0.11

MAX3665-08

-0.12

-0.13

-0.14

-0.15

-0.16

-0.17

COMMON-MODE VOLTAGE (V)

-0.18

-0.19

-0.20

-40 -20 0 20 40 60 80 100

) vs. TEMPERATURE

CC

V

= 3.3V

CC

V

= 5.0V

CC

AMBIENT TEMPERATURE (°C)

MAX3665 toc09

________________Detailed Description

The MAX3665 is a transimpedance amplifier designed
for 622Mbps SDH/SONET applications. It comprises a
transimpedance amplifier, a paraphase amplifier with
CML differential outputs, and a DC cancellation loop.
Figure 1 shows a functional diagram of the MAX3665.

Transimpedance Amplifier

The signal current at IN flows into the summing node of a
high-gain amplifier. Shunt feedback through RFconverts
this current to a voltage. Diodes D1 and D2 clamp the
output voltage for large input currents.

MAX3665

622Mbps, Ultra-Low-Power, 3.3V
Transimpedance Preamplifier for SDH/SONET

4 _______________________________________________________________________________________

_____________________________Typical Operating Characteristics (continued)

(VCC= +3.3V, includes off-chip filter, see Figure 3b, TA= +25°C, unless otherwise noted.)

150

200

300

250

350

400

-40 0-20 20 40 60 80 100

DIFFERENTIAL OUTPUT AMPLITUDE

vs. TEMPERATURE (INPUT = 450µAp-p)

MAX3665 toc10

AMBIENT TEMPERATURE (°C)

PEAK-TO-PEAK AMPLITUDE (mV)

VCC = 5.0V

VCC = 3.3V

EYE DIAGRAM

(INPUT = 10µAp-p)

15mV/div

MAX3665-11

200ps/div

INPUT: 213 - 1 PRBS
CONTAINS 100 ZEROS

EYE DIAGRAM

(INPUT = 450µAp-p)

50mV/div

MAX3665-12

200ps/div

INPUT: 213 - 1 PRBS
CONTAINS 100 ZEROS

_____________________Pin Description

NAME FUNCTION

1

V

CC

+3.3V or +5.0V Supply Voltage

2 IN Signal Input (from photodiode)

PIN

3 N.C.

No Connection. Not internally con­nected.

4 FILT

On-Chip Resistor for Filtering
Photodiode Supply Voltage

7 OUT-

Inverting Voltage Output. Current flow­ing into IN causes V

OUT-

to decrease.

6 OUT+

Noninverting Voltage Output. Current
flowing into IN causes V

OUT+

to

increase.

5, 8 GND Ground

Figure 1. Functional Diagram

V

AMP

CC

1.5k

R1

50Ω

V

CC

R2

R5

50Ω

Q3

D2

D1

R

F

V

CC

IN

Q1

R7

V

CC

PARAPHASE

FILT

V

CC

OUT+

Q2

OUT-

Q5

Q4

REFERENCE AMP

DC

CANCELLATION

AMP

GND

R6

R4

R3

MAX3665