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
1 Supply (V)
Supply Sensitivity
2 (ppm)
Parameter
Values
1.2 V
611.9
Temp Sensitivity (ppm 1e06 ppm(Iref),
.99e06 ppm(Vref)
3 @ 37˚C)
15.15
4 Iref (uA)
5 Iref with ΔVTHn = 10%
ΔIref with ΔVTHp =
6 10%
0.02µA
7 ΔIref with ΔR= 10%
Minimum Supply
8 Voltage(mV)
Maximum Supply
9 Voltage(V)
3.585µA
1.818nA
646.4
1.7
Values
10
TCIref (ppm/˚C)
3323
11
TCVref (ppm/˚C)
3202
12
Power Consumption (µW)
50.23
13
Resistor Value (KΩ)
5.67KΩ
Iref- VDD Sweep
Vref- 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 Vref
PSRR of Iref = 125e6 mho
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
Vdd min =901mV
Vdd max =2.786V
Vref =0.697V
Vref- Temp Sweep
700.9mV @ 37.03C
Iref – Voltage Sweep
Vdd min =904mV
Vdd max =2.788V
Iref =14.61uA
Iref- Temp Sweep
14.69uA @ 37.01C
TCVref
TCIref
Temp sensitivity = 0.39ppm
Voltage Sensitivity - Vref
Temp sensitivity =4.15ppm
Voltage Sensitivity - Iref
Volt sensitivity = 5213ppm
Volt sensitivity = 5229ppm
PSRR for Vref
PSRR for Iref
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%
Temp
3 Sensitivity
(ppm @ 37C)
10
1e06 (Iref)
.99e6 (Vref)
-
4.1(Iref)
0.39(Vref)
-
4
15
15.15
1%
14.69
-2.06%
20
50.23
151.15%
63
215%
Iref (uA)
Power
5 consumption
(uW)
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??