ECE4430 Project Presentation BETA-MULTIPLIER REFERENCE GENERATOR BANDGAP REFERENCE GENERATOR GROUP3 – DEBASHIS BANERJEE JASON PINTO ASHITA MATHEW

DESIGN SPECIFICATIONS Technology Node – TSMC 0.18µm Required Design Specifications Supply voltage 1.2 V Vref 0.7 V Iref 15µA Max Supply Sensitivity 1000ppm Max Temp Sensitivity 10ppm @37 º C Max Power consumption 20uW

BMR -TOPOLOGY USED

BMR- DESIGN CALCULATIONS Using these we get: Sweeping to set current, we get

BMR- ACHIEVED SPECIFICATIONS Parameter Values 1 Supply (V) 1.2 V 2 Supply Sensitivity (ppm) 611.9 3 Temp Sensitivity (ppm @ 37˚C) 1e06 ppm(Iref), .99e06 ppm(Vref) 4 Iref (uA) 15.15 5 Iref with ΔVTHn = 10% 0.02µA 6 ΔIref with ΔVTHp = 10% 1.818nA 7 ΔIref with ΔR= 10% 3.585µA 8 Minimum Supply Voltage(mV) 646.4 9 Maximum Supply Voltage(V) 1.7 Parameter Values 10 TCIref (ppm/˚C) 3323 11 TCVref (ppm/˚C) 3202 12 Power Consumption (µW) 50.23 13 Resistor Value (KΩ) 5.67KΩ

Startup transient response Vref- VDD Sweep Iref- VDD Sweep Vref= 0.718V Startup transient response Startup time:460.6nsec

Current sensitivity with supply voltage = 611.9ppm @37˚C Voltage sensitivity with supply voltage= 9333ppm @37˚C

PSRR of Vref = 40dB PSRR of Iref PSRR of Iref = 125e6 mho PSRR of Vref

Iref changes by 1.818nA for +-10% variation in Vthp Iref changes by 0.02uA for +-10% variation in Vthn

TCIref of 3323 ppm/ ˚C at 37 ˚C TCVref of 3202ppm/ ˚C @ 37˚C

BGR TOPOLOGY USED

DIFFERENTIAL AMP STRUCTURE

BGR DESIGN CALCULATIONS With the above values of L,N,R we observed that the ICTAT and IPTAT fail to cancel out exactly at 37 deg C. So through simulations we have adjusted R,L,N to obtain the desired characteristics. The values obtained are L = 8.5, N=4.84, R= 9.84K

ACHIEVED SPECIFICATIONS Parameter Specs obtained 1 Supply (V) 1.2 V 2 Vref (V) 0.698V 3 Supply Sensitivity (ppm) 5213ppm 4 Temp Sensitivity (ppm @ 37C) 0.39ppm 5 Power consumption (uW) 63uW 6 Iref (uA) 14.69uA 7 ΔIref with ΔVTHn = 10% 124.8nA 8 Δ Iref with ΔVTHp = 10% 1.925nA 9 ΔIref with ΔR= 10% 3.1uA 10 Minumum Supply Voltage 901mV 11 Maximum Supply Voltage 2.786V 12 TCIref 0.13ppm/deg C 13 TCVref (ppm) 1.258e-3 ppm/deg C 14 PSRR for Vref 53.2dB 15 PSRR for Iref 2.18e+7 mho

Vref – Voltage Sweep Iref – Voltage Sweep Vref- Temp Sweep Vdd min =901mV Vdd min =904mV Vdd max =2.786V Vdd max =2.788V Vref =0.697V Iref =14.61uA Vref- Temp Sweep Iref- Temp Sweep 700.9mV @ 37.03C 14.69uA @ 37.01C

Voltage Sensitivity - Vref Voltage Sensitivity - Iref TCVref TCIref Temp sensitivity = 0.39ppm Temp sensitivity =4.15ppm Voltage Sensitivity - Vref Voltage Sensitivity - Iref Volt sensitivity = 5213ppm Volt sensitivity = 5229ppm

PSRR for Iref PSRR for Vref Start up delay Power consumption PSRR = 2.18*107 mho PSRR = 53.2dB Start up delay Power consumption Power consumption= 63uW Start up delay = 189ns

Δ IREF WITH VTH VARIATION Δ IREF for 10% variation in Vthp = 1.925nA Δ IREF for 10% variation in Vthn = 124.8nA

DEVIATION FROM SPECS Parameter Specs BMR Specs Obtained BMR Specs Error BGR Specs obtained BGR Specs Error 1 Vref (V) 0.7 0.718V 2.65% 0.698V 0.28% 2 Supply Sensitivity (ppm) 1000 611.9 (Iref) -38.81% 5213 (Vref) 421.3% 3 Temp Sensitivity (ppm @ 37C) 10 1e06 (Iref) .99e6 (Vref) - 4.1(Iref) 0.39(Vref) 4 Iref (uA) 15 15.15 1% 14.69 -2.06% 5 Power consumption (uW) 20 50.23 151.15% 63 215%

CONCLUSION Temperature sensitivity was observed to be better in a BGR than compared to a BMR because there is PTAT and CTAT cancellation. Voltage sensitivity is much better in BMR than in BGR. Supply sensitivity is better with stacked devices , but since the supply voltage is small, we cannot use cascode topology. Both BMR and BGR are supposed to work at low frequency. So we used a min value of L = 4*0.18um. This led to a high output impedance and hence lesser voltage sensitivity. Careful design of a high gain differential amplifier would lead to a much better voltage sensitivity.

Thank you… Questions??