DS1843D+

Overview

The DS1843D+ is a fast sample-and-hold circuit manufactured by Analog Devices Inc./Maxim Integrated, designed for capturing high-speed signals in space-constrained environments. It features a differential switched-capacitor input stage, offset nulling, and a buffered output. The device operates on a single supply voltage ranging from 2.97V to 5.5V with a typical supply current of 5.7mA. Key electrical parameters include a minimum sample time of 300ns, an output delay of 2µs, and a hold time of 100µs. It is housed in an 8-pin µDFN package measuring 2mm x 2mm and supports an operating temperature range from -40°C to +85°C.

Feature Summary

• Fast Sample Time: Optimized for rapid signal acquisition with a minimum sample time of 300ns.
• Low Input Offset: Includes internal offset nulling circuitry to minimize total input referenced voltage offset.
• Buffered Output: Features a differential or single-ended output buffer for stable signal transmission.
• Compact Package: Available in a small, lead-free 8-pin µDFN (2mm x 2mm) surface-mount package.

Applications

• Gigabit Passive Optical Network (GPON) OLT
• Gigabit Ethernet Passive Optical Network (GEPON) OLT
• GPON Optical Network Unit

Procurement Notes

Verify the specific ordering suffix when purchasing. The base part number DS1843D+ indicates a tube package, while the TRL suffix denotes tape and reel packaging. Confirm that the component meets RoHS compliance requirements as indicated by the plus sign in the part number. Ensure the selected package type matches your assembly equipment capabilities before placing orders.

Selection Notes

Select the DS1843D+ for applications requiring a compact sample-and-hold amplifier with low input capacitance. Consider the 5pF sampling capacitor and 7pF parasitic input capacitance when designing input circuits to ensure proper settling times. Verify that the external ADC sampling speed accommodates the device's output recovery time for accurate data capture.

Part Context

The DS1843 belongs to the Maxim Integrated family of fast sample-and-hold circuits. It is specifically optimized for optical line transmission systems, particularly for burst-mode RSSI measurements using an external sense resistor. The device integrates a fully differential sampling capacitor and switches with a dedicated output buffer, making it suitable for fiber optic burst-mode systems.

Replacement Considerations

DS1843D+TRL

FAQ

How does the DEN pin affect the output configuration?

Connecting the DEN pin to VCC enables differential output mode, while connecting it to GND configures the device for single-ended output operation.

What is the purpose of the SEN pin?

The SEN pin is the Sample Enable input. When pulsed high, it enables the input sampling process; it must be pulled low to initiate the hold phase.