Topology

1
Topology
2
Conceptual Design
3
OCR Bode plots at 100Hz and 10KHz

• High frequency attenuation gt75dB
• Attenuation at 0.1Hz 53dB

• Low frequency rolloff begins at 40Hz
• Passband ripple of 0.5dB

4
Stability (Vref step)

• No overshoot
• Settles to 5 in 15ns

5
Specifications
Required Achieved Bonus?
Power _at_ 10kHz lt30uW 9uW Yes
High Freq. Attenuation gt50dB 75dB Yes
Peak Overshoot lt10 None Yes
Settling Time lt50ms 15ms Yes
OCR Range _at_ Vref1.56V gt50mV 0.84/-1.46V Yes
OCR Module Power lt500nW 8.2nW Yes
Area 0.25mm2 0.15mm2 Yes
Passband Ripple lt1dB 0.5dB Yes
Low Freq. Rolloff Freq. lt50Hz 40Hz Yes
Power-on Startup Time lt1s 250ms Yes
0.1Hz Attenuation gt50dB 53dB No
Dynamic Range gt60dB 60dB No
Noise 817uV
Maximum Linear Input Signal 0.82V
6
Other Features

• Biasing circuitry mirrors on-chip current
  reference while still providing orthogonal tau
  and Q control

• At Vref2.1V, the output varies by less than 1mV
  over the entire input range!

7
Layout

• Core layout density 2.5x higher than provided
  current reference layout according to L-Edit
• Highly common-centroid