11/17/2011

1

BMR and BGR Generator Design

Man Li

Andy Montoya

Andrew Malinowski

Design Specifications

Process AMI-0.5um

Supply 3.3V

Vref 1.26 V

Max Supply Sensitivity 1000ppm within 10% of supply

Max Temperature Sensitivity 50 ppm @ 50C

Max Power Consumption 5 uW

Iref 0.25 uA

11/17/2011

2

Beta Multiplier Schematic

Beta Multiplier Calculations

K=2.6

11/17/2011

3

Vthn Sweep

For Vthn= -10%, Iref = -208.9 pA and Vref = -677.77 mV.For Vthn = 10%, Iref = 175.6 pA and Vref = 67.91 mV.

Vthp Sweep

For Vthp= -10%, Iref = -131.9pA and Vref = -103uV.For Vthp = 10%, Iref = 107.4pA and Vref = 83.97uV.

11/17/2011

4

Resistor R Sweep

For R= -10%, Iref = 28.06 nA and Vref = 21.54 mV.For R = 10%, Iref = -22.94 nA and Vref = -18.27 mV.

Min, Max Supply Voltage

Supply Voltages between 2.057 V and 4.449 V produce reference values within 1% of the specification.

11/17/2011

5

Temperature Sweep

Temperature Sensitivity, Iref

Temperature Sensitivity of Iref at 50C: 1047.5 ppm

11/17/2011

6

Temperature Sensitivity, Vref

Temperature Sensitivity of Vref at 50C: 321.12 ppm

Supply Sweep

11/17/2011

7

Supply Sensitivity, Iref

Max Supply Sensitivity of Iref: 572.34 ppm

Supply Sensitivity, Vref

Max Supply Sensitivity of Vref: 89.7 ppm

11/17/2011

8

BMR Performance Recap

Parameter Specification Achieved Value

Supply Sensitivity 1000 ppm 89.7 ppm (Vref)

1000 ppm 572.34 ppm (Iref)

Temp Sensitivity @50C 50 ppm 321.12 ppm (Vref)

50 ppm 1047.5 ppm (Iref)

Power Consumption 5 uW 3.36uW

Min, Max Supply Voltage Min:2.057 V, Max:4.449 V

Resistor Value 80.5k

PSRR -41.25dB (Vref); -10.08dB (Iref)

Startup Delay

11/17/2011

9

Diff-Amp Used in BGR

Bandgap Calculations

11/17/2011

10

Vthn Sweep

For Vthn= -10%, Iref = 3.3nA and Vref = -66mV.For Vthn = 10%, Iref = -3.5nA and Vref = 66mV.

Vthp Sweep

For Vthp= -10%, Iref = -100pA and Vref = -10uV.For Vthp = 10%, Iref = 100pA and Vref = 5uV.

11/17/2011

11

Resistor R Sweep

For R= -10%, Iref = 2.6nA and Vref = 55uV.For R = 10%, Iref = -2.5nA and Vref = -20uV.

Min, Max Supply Voltage

Supply Voltages between 1.782 V and 6.707 V produce reference values within 1% of the specification.

11/17/2011

12

Temperature Sweep

Temperature Sensitivity, Iref

Temperature Sensitivity of Iref: 71.04 ppm

11/17/2011

13

Temperature Sensitivity, Vref

Temperature Sensitivity of Vref: 61.22 ppm

Temperature Sensitivity, Vref

Supply Sensitivity of Vref: 63.8 ppmSupply Sensitivity of Iref: 1740 ppm

11/17/2011

14

BGR Performance Recap

Parameter Specification Achieved Value

Supply Sensitivity 1000 ppm 63.85 ppm (Vref)

1000 ppm 1740 ppm (Iref)

Temp Sensitivity @50C 50 ppm 61.22 ppm (Vref)

50 ppm 71.04 ppm (Iref)

Power Consumption 5 uW 2.19uW

Min, Max Supply Voltage Min: 1.782V, Max: 6.707V

Resistor Value 500k, 2400u

PSRR -11.12dB (Vref), 15.17dB (Iref)

Startup Delay

11/17/2011

15

Questions?

Thanks!