Homework Statement

Mao-Cheng Chiu

National Chiao -Tung University

Department of Electronics Engineering

Specification of the TIA Format of report Topology examples Using HSPICE to Analyze Performance

Outline

Technology 0.18m CMOS

CPD 0.5pF

Supply Voltage 1.8V

Data Rate 1.25Gb/s

Transimpedance Gain > 10k-3dB Bandwidth > 1GHz

Input Referred Noise Current< 0.15Arms

(1M to 1GHz)

Overload As large as possible

Deterministic Jitter < 100pspp

Power Consumption < 100mW

Homework 1: TIADue Date: May 10, 2007

• Design Homework– Circuit Architecture– Circuit Analysis– Simulation• DC/AC/Noise/Eye diagrams (for sensitivity and

overload levels)

– Summary• Comparison with target spec.

• Pros & Cons

Report Outline

Examples of Multi-Stage TIA

RF

M. Ingels, et al., IEEE JSSC, Dec. 1994

S. Yamashita, et al., IEEE JSSC, July. 2002

• Example:

AC analysis

Is 0 1 ac 1

.ac dec 10 1k 5g

.meas ac midgain FIND vdb(vo) AT=100MegHz

.meas ac bandwidth when vdb(vo)='midgain-3.0' FALL=1

.meas ac maxgain max vdb(vo)

Input signal

AC analysis

Gain & bandwidth.probe Gain= par('vdb(vo)-idb(Is)')+ phase= par('vp(vo)-ip(Is)')

.noise v(vo) Is 1 total equivalent input referred noise from 1k to 5g

• BER= 10-12 =Q(Iin,pp/2In,in,rms) Iin,pp/2In,in,rms =7

Iinpp = 14 In,in,rms = Sensitivity

Sensitivity = Iinpp = 14 In,in,rms = 14* 0.264uA =3.7uA

AC analysis• Simulation result:

• Example: 2.5Gb/s K28.5 pattern

---00111110101100000101-----.param h = 50uIin 0 g1 pwl(+0.00ns h+0.20ns 0 0.800ns 0 +1.00ns h 2.800ns h+3.00ns 0 3.200ns 0+3.40ns h 3.600ns h+3.80ns 0 4.000ns 0+4.20ns h 4.800ns h+5.00ns 0 6.800ns 0+7.00ns h 7.200ns h+7.40ns 0 7.600ns 0+7.80ns h 8.000ns h+R 0)

PRBS Pattern

0 0 1 1 1 ….0 0 1 1 1 ….

• Rise time and fall time are both half of the bit time.

• K28.5 contains five consecutive 1’s and five consecutive 0’s.

•“h” is the magnitude of the input signal.

0.4ns

• Example: .param width_eye =1.6ns phase=0ns .probe tran TIME_1.25G=par('TIME+phase-int((TIME+phase)/width_eye)*width_eye')

Eye Diagram

Phase

Width_eye

• X-Axis = TIME_1.25G

Jitter & Overload

•Measurement of Jitter :

•Overload:

Increases the input level and then check the output signal in the eye diagram.

Jitter (p-p) Iin,pp= 3.7u ,Vout,pp= 5.1mV

Iin,pp= 370u , Vout,pp= 0.52V

Iin,max = overload