Technical Report 4 for Pittsburgh Digital Greenhouse

1. Technical Report 4 for Pittsburgh Digital Greenhouse High Speed CMOS A/D Converter Circuit for Radio Frequency Signal Kyusun Choi Computer Science and Engineering Department The Pennsylvania State University

2. Project Goals Core development and silicon test of 6 and 8 bit TIQ based flash ADC • High speed circuit and layout design • 2. Prototype chip fabrication • 0.25um and 0.18um CMOS • 3. Test and evaluate, explore and improve

3. Project Milestones • 1st Chip design, 0.25um 12/01/2000 • Chip fabrication 02/05/2001 • Chip testing 04/04/2001 1st report • 2nd chip design, 0.18um 07/10/2001 2nd report, chip • Chip fabrication 10/08/2001 • Chip testing 11/09/2001 3rd report • Project ending 12/31/2001 Chip • Project presentation 02/15/2002 Final report

4. Project Feature • High speed ADC, 1 GSPS • RF applications • SOC applications, digital CMOS • Future-ready, < 0.10um, < 1.0V

5. gain booster V1 Vin gain booster V2 D1 D2 gain booster D3 V3 Dk gain booster circuit gain booster Vn Thermometer code to binary encoder TIQ flash ADC

6. Other flash ADC Vref V1 – + Vin R V2 V1 – + R D1 D2 V3 V2 D3 – + R V3 Dk – + R Vn Vn Thermometer code to binary encoder Resistor ladder circuit

7. _ + Vin Vout Vin Vm Vout Vr Vout Vout Vr Vin Vm Vin TIQ comparator DIFFERENTIAL INPUT VOLTAGE COMPARATOR INVERTER Vr is provided by a voltage references source, External to the voltage comparator Vm is an internal parameter of an inverter, fixed by the transistor sizes

8. TIQ comparator • High speed • Less area • No resistor ladder and reference voltages • No capacitor switching • Future ready • Scale down • Low supply voltage • Standard digital logic technology • Ideal for SOC

9. Prototype Test Results 1st prototype chip (0.25um), six ADCs on chip

10. Prototype Test Results 2nd prototype chip (0.18um), ten ADCs on chip

11. Prototype Test Results ADC: 6 bit 1.00um, ROM, 0.18um prototype chip Input: 100 KHz Saw wave

12. Prototype Test Results ADC: 6 bit 1.00um, FAT, 0.18um prototype chip Input: 100 KHz Saw wave

13. Prototype Test Results ADC: 9 bit 1.00um, ROM, 0.25um prototype chip Input: 100 KHz Saw wave

14. Prototype Test Results ADC: 6 bit 1.00um, FAT, 0.18um prototype chip Input: DC DNL = 0.36 LSB INL = 1.36 LSB

15. Prototype Test Results ADC: 6 bit 1.00um, FAT, 0.18um prototype chip Input: 80KHz sign wave, f_sample = 10 MHz SNR = 23.40 dB SNDR = 21.83 dB SFDR = 9.13 dB ENOB = 3.33 bits

16. Prototype Test Results ADC: ideal 6 bit Input: 1MHz sign wave, f_sample = 200 MHz SNR = 37.78 dB SNDR = 36.56 dB SFDR = 37.86 dB ENOB = 5.78 bits

17. Summary • High speed ADC for RF application • ADC core - 6 and 8 bit design • prototype chips (silicon test) • 0.25 m and 0.18 m • CMOS digital logic technology • SOC beyond 0.10um & 1.00V

18. Innovation/enhancement challenges • 1 GSPS with digital CMOS • Custom layout generation and • modeling CAD tool • 8bit and 10bit ADC • Low power • Low noise • Dynamic calibration • Offset • Gain • Temperature • Power supply voltage • Process parameter variation

19. Summary • High speed ADC for RF application • ADC core - 6 and 8 bit design • prototype chips (silicon test) • 0.25 m and 0.18 m • CMOS digital logic technology • SOC beyond 0.10um & 1.00V