Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - buffer amplifiers, repeaters PCIe 5 GBit/s TQFN 42 EP

General Description

The MAX4950 PCI Express (PCIe

) quad equalizer/

redriver operates from a single +3.3V supply. This

device improves signal integrity at the receiver through

programmable input equalization and programmable

redrive circuitry. The output circuitry reestablishes de-

emphasis lost on the board, compensating for circuit

board loss. This device permits optimal placement of

key PCIe components and longer runs of stripline,

microstrip, or cable.

The MAX4950 contains four identical buffers capable of

equalizing differential signals at data rates up to 5GT/s,

and features electrical idle and receiver detection on

each channel. The MAX4950 is ideal for use with PCIe

Gen I (2.5GT/s) and Gen II (5.0GT/s) data rates and

features a power-saving mode.

The MAX4950 is available in a small, lead-free, 42-pin

(3.5mm x 9.0mm) TQFN package for optimal layout and

minimal space requirements. The board traces are flow-

through for ease of layout. The MAX4950 is specified

over the 0°C to +70°C operating temperature range.

Applications

Servers

Industrial PCs

Test Equipment

Desktop Computers

Laptop Computers (for External Video Cards)

Communications Switchers

Storage Area Networks

Features

♦ Single +3.3V Supply Operation

♦ Generation I (2.5GT/s) and Generation II (5.0GT/s)

Capable

♦ Return Loss:

≥ 10dB (f ≤ 1.25GHz)

≥ 8dB (f ≤ 2.5GHz)

♦ Very Low Latency

280ps Propagation Delay

♦ Individual Lane Detection

♦ Low Lane-to-Lane Skew: ±50ps

♦ Total Jitter ≤ 35ps

P-P

at BER = 10

-12

♦ Three-Level-Programmable Input Equalization

♦ Three-Level-Programmable Output Deemphasis

♦ On-Chip 50Ω Input/Output Terminations

♦ ±2kV Human Body Model (HBM) Protection on All

Pins

♦ Space-Saving, 3.5mm x 9.0mm, TQFN Packaging

MAX4950

Quad PCI Express Equalizer/Redriver

________________________________________________________________

Maxim Integrated Products

19-4439; Rev 0; 5/09

EVALUATION KIT

AVAILABLE

TOP VIEW

MAX4950

TQFN

INEQ1

INEQ0

OEQ1

OEQ0

P_SAV

O_AMP

RX_DET

1234567891011121314151617

38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22

IN2N

GND

IN3P

IN3N

GND

IN2P

GND

IN1N

IN1P

GND

IN0N

IN0P

GND

OUT2N

GND

OUT3P

OUT3N

GND

OUT2P

GND

OUT1N

OUT1P

GND

OUT0N

OUT0P

GND

*CONNECT EXPOSED PAD (EP) TO GND.

*EP

Pin Configuration

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX4950CTO+ 0°C to +70°C 42 TQFN-EP*

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim's website at www.maxim-ic.com.

PCIe is a registered trademark of PCI-SIG Corp.

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

Summary of content (10 pages)

PAGE 1
9-4439; Rev 0; 5/09 KIT ATION EVALU E L B AVAILA Quad PCI Express Equalizer/Redriver Features (PCIe®) ♦ Single +3.3V Supply Operation The MAX4950 PCI Express quad equalizer/ redriver operates from a single +3.3V supply. This device improves signal integrity at the receiver through programmable input equalization and programmable redrive circuitry. The output circuitry reestablishes deemphasis lost on the board, compensating for circuit board loss.
PAGE 2
MAX4950 Quad PCI Express Equalizer/Redriver ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND.) VCC ........................................................................-0.3V to +4.0V All Other Pins (Note 1)................................-0.3V to (VCC + 0.3V) Continuous Current IN_P and IN_N..................................±30mA Peak Current IN_P and IN_N (pulsed for 1µs, 1% duty cycle)............................................................
PAGE 3
Quad PCI Express Equalizer/Redriver (VCC = +3.0V to +3.6V, CCL = 75nF coupling capacitor on each output, RL = 50Ω resistor on each output, TA = 0°C to +70°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN f = 0.05GHz to 1.25GHz 10 f = 1.25GHz to 2.5GHz 8 RLTX-CM f = 0.05GHz to 2.5GHz 6 Redriver Operation Differential Input Signal Range VRX-DIFF-PP f = 0.05GHz to 2.
PAGE 4
MAX4950 Quad PCI Express Equalizer/Redriver ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.0V to +3.6V, CCL = 75nF coupling capacitor on each output, RL = 50Ω resistor on each output, TA = 0°C to +70°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.
PAGE 5
Quad PCI Express Equalizer/Redriver 200 0 -200 -400 200 0 -200 EYE DIAGRAM VOLTAGE (mV) 400 EYE DIAGRAM VOLTAGE (mV) 400 INEQ0 = INEQ1 = 0, O_AMP = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 1 MAX4950 toc02 600 MAX4950 toc01 600 EYE DIAGRAM VOLTAGE (mV) INEQ0 = INEQ1 = 0, O_AMP = 0, VIN = 200mVP-P, OEQ0 = 1, OEQ1 = 0 -400 -600 MAX4950 toc03 INEQ0 = INEQ1 = 0, O_AMP = 0, VIN = 200mVP-P, OEQ0 = 0, OEQ1 = 0 500 400 300 200 100 0 -100 -200 -300 -400 -500 -600 -150ps-100ps -50ps 0ps 0 -100 -200 -300 -40
PAGE 6
Typical Operating Characteristics (continued) (VCC = +3.3V and TA = +25°C, unless otherwise noted. All eye diagrams measured using K28.5 pattern.
PAGE 7
Quad PCI Express Equalizer/Redriver PIN NAME 32 OUT1N Inverting Output 1 FUNCTION 33 OUT1P Noninverting Output 1 35 OUT0N Inverting Output 0 36 OUT0P Noninverting Output 0 39 EN 40 RX_DET 41 O_AMP Output Redrive Selection Input. O_AMP is internally pulled down by 60kΩ (typ) resistor. 42 P_SAV Power-Save Mode Input. P_SAV is internally pulled down by 60kΩ (typ) resistor. See Table 6. — EP Exposed Pad. Internally connected to GND.
PAGE 8
MAX4950 Quad PCI Express Equalizer/Redriver Detailed Description The MAX4950 quad equalizer/redriver is designed to support both Gen I (2.5GT/s) and Gen II (5.0GT/s) PCIe data rates. The device contains four identical drivers with idle/receive detect on each lane and equalization to compensate for circuit-board loss. Signal integrity at the receiver is improved by the use of programmable input equalization circuitry.
PAGE 9
Quad PCI Express Equalizer/Redriver MAX4950 Table 5. Power-Save Mode Quiescent Power Dissipation EN P_SAV O_AMP QUIESCENT POWER SUPPLY CURRENT (typ) (mA) QUIESCENT POWER SUPPLY CURRENT (max) (mA) QUIESCENT POWER DISSIPATION (3.3V, typ) (mW) QUIESCENT POWER DISSIPATION (3.
PAGE 10
MAX4950 Quad PCI Express Equalizer/Redriver Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 42 TQFN-EP T423590+1 21-0181 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.