Table 1.

Electrical performance Summary and comparison of the proposed single-pixel stimulator (SPStim).

	[18]	[6]	[12]	[13]	[3,18,19,20]	This Work
CMOS Process	0.35-μm standard	0.18-μm CIS **	0.18-μm CIS **	0.35-μm BCD ***	0.35-μm CIS **	0.35-μm standard
Supply voltage [V]	5	± 1.65	0.5, 1.8	5, 12	± 2	± 1.65
Chip area [mm2]	1.0 × 2.7	2.2 × 2.2	1.9 × 1.9	2.5 × 1.2	3 × 3.5	4.3 × 3.2
Single pixel area [μm2]	200 × 200	127 × 167	30 × 30	55 × 50	30 × 30	114 × 117
Dynamic range [Lux]	-	400–1200	1–1000	100–250	0.1–10,000	400–1600
Pulse amplitude * [μA]	50–1050	0–343	0–50	0–300	0–100	0–143
On-chip digital controller	Yes	No	Yes	No	Yes	Yes
Pulse width * [ms]	-	-	-	-	4	0.5–5
Pulse period * [ms]	-	-	60	-	3–100	1–50
Interphase delay * [ms]	-	-	-	-	0 ms	0–2 ms
Mismatch [%]	-	4.85	-	-	-	1.12
Stimulation method	Charge-balanced biphasic current stimulation

* Pulse: Biphasic Pulse, ** CIS: CMOS Image Sensor, *** BCD: Bipolar CMOS and Double diffused MOS(DMOS).