Avalanche photodiode (APD) module C30645 series

Product Overview
The C30645 Series consists of large-area InGaAs avalanche photodiodes (APDs) with an 80 µm active area optimized for 1000–1700 nm detection. Available in hermetic TO-18 and TO-46 packages, ceramic carrier and SMD carriers, these APDs offer high responsivity at 1550 nm and options for enhanced low-noise performance suitable for high-speed fiber-optic and sensing systems.

Applications and Benefits
Designed for OEM and system integrators, the C30645 Series provides a balance of bandwidth and noise performance to improve signal-to-noise ratio (SNR) in demanding applications.

• LiDAR and eye-safe range finding — increased detection range with low-noise variants
• Coherent OTDR and distributed fiber sensing (DTS, DAS) — improved sensitivity for Raman-scattered or backscattered signals
• High-speed telecommunication receivers and optical test equipment — wide bandwidth and fast rise/fall times

Models and Package Options

• C30645ECERH | Ceramic carrier | Window: N/A | Aperture: N/A
• C30645EH | TO-18 (2-pin) | Window: Silicon | Aperture: Small (AR-coated option)
• C30645EH-1 | TO-18 (2-pin) | Window: Glass | Aperture: Large (AR-coated option)
• C30645EH-2 | TO-46 (3-pin) | Window: see table | Comment: 3 = ground pin
• C30645EH-7 | TO-18 (2-pin) | Window: Silicon | Aperture: Small | low-noise option
• C30645EH-27 | TO-46 (3-pin) | Window: Glass | Aperture: Large | low-noise, 3 = ground pin
• C30645L-080 | SMD | Window: Glass | Aperture: N/A
• C30645L-080-1 | SMD | Window: Silicon | Aperture: N/A
• C30645L-080-7 | SMD | Window: Glass | Aperture: N/A | low-noise option
• C30645L-080-17 | SMD | Window: Silicon | Aperture: N/A

Notes
Note 1: Glass windows transmit visible and IR wavelengths; silicon windows block visible light up to ~1.1 µm.
Note 2: AR-coated window option for reduced reflections and improved throughput.

Electrical / Optical Specifications

• Active area: 80 µm
• Spectral range: 1000–1700 nm
• Typical responsivity @1550 nm: 9.3 A/W
• Typical rise/fall time: 0.3 ns
• Minimum bandwidth (f3dB): 1000 MHz
• Capacitance: typical 1.25 pF (standard), 1.45 pF (SMD)
• Dark current (typical): 2.5 nA (standard), 1 nA (SMD); max: 15 nA (standard), 5 nA (SMD)
• Dark noise (typical): 0.2 pA/√Hz (standard); low-noise: 0.1 pA/√Hz
• NEP (typical): 25 fW/√Hz (standard); low-noise: 11 fW/√Hz
• Operating gain (M): min 10, typical 20
• Breakdown voltage (V_BD): min 45 V, typ 50 V, max 70 V
• Temperature coefficient of V_BD: typ 0.14 V/°C, max 0.2 V/°C

Key features

• 80 µm active area for high collection efficiency
• Optimized for 1000–1700 nm fiber and eye-safe wavelengths
• Low-noise option for extended range and sensitivity
• Multiple package options: TO-18, TO-46, ceramic carrier, SMD
• High bandwidth and sub-nanosecond rise/fall times for high-speed systems
• Low capacitance suitable for fast detector front-ends