High Responsivity Detection from UV to Infrared

The SM3320A is an image sensor IC that incorporates a single-element photodiode and optical detection circuit in an ultrasmall package. In the field of authentication of currency and securities, the demand for authentication using wavelengths from UV to infrared for improved security performance has been growing. However, in existing optical detector circuits, a general-use photodiode and op amp are required for different wavelengths, which places limits on the design and degree of freedom of wavelength detection.
The SM3320A uses a 1mm2 photodiode and charge storage amplifier, its responsivity can be controlled using a serial interface, it can detect wavelengths ranging from UV to infrared with high responsivity, and it can also compensate for variations in LED intensity. It also features a dark current compensation circuit, enabling it to generate a stable output signal within the operating temperature range. In addition, several SM3320A devices can be connected in parallel to increase the width of detection, allowing it to support a wide range of optical detection systems.



  • High-precision preamplifier for UV to visible light to infrared detection using a single IC
  • Dark current compensation circuit built-in for stable signal outputs
  • External gain setting configurable to suit the detection wavelength
  • Gain setting and sensor output control: Serial interface (DATA, SE, CLK, OE)
  • Transimpedance*1 setting range: 500kΩ to 240MΩ
  • Built-in anti-reflective film for minimal responsivity variation due to wavelength
  • Photodiode size: 2.3mm × 0.6mm (sensor surface area: 1.0mm2)
  • Supply voltage range: 2.7 to 5.5V (single supply)
  • Operating temperature range: -40 to +85°C
  • Package: 12-pin HCOB, 3.20mm (W) × 5.50mm (D) × 1.15mm (H)

*1. Transimpedance: Equivalent resistance value of a current-to-voltage converter circuit.

Detector with single wideband sensor

Detector with single wideband sensorDetector with single wideband sensor

Spectral Responsivity Characteristic

Spectral Responsivity Characteristic

Block Diagram


Typical Application Circuit

Parallel connection in the form of an array is supported using three address bits (A0, A1, A2). All input/output control is performed using a serial interface (DATA, SE, CLK, OE). This allows you to set the responsivity in the incident wavelength region and compensate for variations in LED intensity.応用回路例


3320_ND13001E00(476.9 KB)

Application Note

APP_SM3320A_E(373.5 KB)