DS1878：SFP+ Controller with Digital LDD Interface _ BDTIC a Leading Distributor in China

DS1878：SFP+ Controller with Digital LDD Interface

Meets All SFF-8472 Control and Monitoring Requirements

The DS1878 controls and monitors all functions for SFF, SFP, and SFP+ modules including all SFF-8472 functionality. The combination of the DS1878 with Maxim laser driver/limiting amplifier solutions supports VCSEL, DFB, and EML-based solutions. The device provides APC loop, modulation current control, and eye safety functionality. It continuously monitors for high output current, high bias current, and low and high transmit power to ensure that laser shutdown for eye safety requirements are met without adding external components. Six ADC channels monitor VCC, temperature, and four external monitor inputs (MON1–MON4) that can be used to meet all monitoring requirements. MON3 is differential with support for common mode to VCC. Two digital-to-analog (DAC) outputs with temperature-indexed lookup tables (LUTs) are available for additional control functionality.

Key Features

Meets All SFF-8472 Control and Monitoring Requirements
Laser Bias Controlled by APC Loop and Temperature LUT to Compensate for Tracking Error
Laser Modulation Controlled by Temperature LUT
Six Analog Monitor Channels: Temperature, VCC, MON1–MON4
- MON1–MON4 Support Internal and External Calibration
- Scalable Dynamic Range
- Internal Direct-to-Digital Temperature Sensor
- Alarm and Warning Flags for All Monitored Channels
Two 9-Bit Delta-Sigma Outputs with 36 Entry Temperature LUTs
Digital I/O Pins: Five Inputs, Four Outputs
Comprehensive Fault-Measurement System with Maskable Laser Shutdown Capability
Flexible, Two-Level Password Scheme Provides Three Levels of Security
256 Additional Bytes Located at A0h Slave Address
I²C-Compatible Interface
3-Wire Master to Communicate with a Maxim Laser Driver/Limiting Amplifier
+2.85V to +5.5V Operating Voltage Range
-40°C to +95°C Operating Temperature Range
28-Pin TQFN (5mm x 5mm x 0.75mm) Package

DS1878: Typical Operating Circuit

Applications/Uses

SFF, SFP, and SFP+ Transceiver Modules

DataSheet

title	Download file
DS1878 Data Sheet	DS1878.pdf

Parametrics

Part Number	ADCs	Resolution (bits)	DACs/ Resistors	FS Out (kΩ)	Steps	Temp. Sensor	Memory	V_SUPPLY (V)	Control Interface	Package/Pins	Budgetary Price
Part Number	ADCs	Resolution (bits)	DACs/ Resistors	FS Out (kΩ)	Steps	Temp. Sensor	Memory	V_SUPPLY (V)	Control Interface	Package/Pins	See Notes
DS1878	5-Input Muxable	13	2 DACs	None	None	Internal	EEPROM	2.85 to 3.9	I2C	TQFN/28	$1.74 @1k

Quality and Environmental Data

DS1878.pdf

Ordering Information

Part Number	Status	Recommended Replacement	Package	Temp	RoHS
DS1878T	No Longer Available	DS1878T+	TQFN,;28 pin;26 mm²	-40°C to +85°C	No
DS1878T+	Active		TQFN,;28 pin;26 mm²	-40°C to +85°C	Lead Free
DS1878T+T	Active		TQFN,;28 pin;26 mm²	-40°C to +85°C	Lead Free
DS1878T+T&R	No Longer Available	DS1878T+T	TQFN,;28 pin;26 mm²	-40°C to +85°C	Lead Free
DS1878T-T	No Longer Available	DS1878T+T	TQFN,;28 pin;26 mm²	-40°C to +85°C	No