DS3920 MAXIM | Alldatasheet

Document overview

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Technical content

Features

S Wide Voltage Input Range: 2.97V to 76V S Current Monitor  Wide 250nA to 2mA Range  5:1 Mirror Ratio  Fast 50ns Time Constant S Current Clamp (2.9mA or 20mA, typ) S Voltage Clamp Protects Subsequent Output Circuitry S 6-Pin SOT23 (MAX4007 Compatible)

Applications

Avalanche Photodiode (APD) Biasing PIN Photodiode Monitoring GEPON, GPON, 10GEPON, XGPON: ONU and OLT Ordering Information appears at end of data sheet. For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/DS3920.related DS3920 IMIROUT IMIROUT/5 THERMAL SHUTDOWN CURRENT MONITOR CURRENT LIMIT MIROUT MIRIN DIODE 3.3V APD BIAS MIR IMIROUT/5 APD ROSA GND VOUT RAGC 499Ω CFILTER 0.1/uni03BCF ROUT RFILTER TIA For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Maxim Integrated Products 2 DS3920 Fast Current Mirror Voltage Range on MIRIN, MIROUT, Voltage Range on MIR Continuous Power Dissipation (TA = +70NC) ABSOLUTE MAXIMUM RATINGS Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera- tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 1: See the Typical Application Circuit. Note 2: 1V DC change applied to MIRIN; 100 FA at MIROUT; 4.99kI load to ground on MIR. Note 3: Guaranteed by design; not production tested. Note 4: Rising MIROUT transition from 10FA to 1mA; 15V < VOUT < 76V.

ELECTRICAL CHARACTERISTICS

(VMIRIN = 2.97V to 76V, TA = -40NC to +85NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS MIRIN Voltage VMIRIN 2.97 76 V MIRIN Current IMIRIN IMIROUT = 2.5mA 4.4 mA Diode Forward Current IDF 5 mA Diode Forward Voltage VDF IDF = 100FA, TA = +25NC 0.6 V IDF = 5mA, TA = +25NC 1.25 MIROUT Current Limit IMIROUT DS3920T-001 version 10 20 40 mA DS3920T-002 version 2 2.9 4.4 MIROUT Series Resistance RAGC (Note 1) 100 W MIR to MIROUT Ratio KMIR 1FA to 2.5mA 0.190 0.200 0.210 A/A IMIROUT > 2.5mA 0.180 0.200 0.220 Power-Supply Rejection Ratio (DIMIR/IMIR) /DVMIRIN VMIRIN = 3V (Note 2) 4800 15,000 ppm/V VMIRIN = 30V or 60V (Notes 2, 3) 100 500 MIR Current Rise Time (20%/80%) tRC (Note 4) 30 ns Thermal Shutdown Temperature TSHDN (Note 3) +150 NC Thermal Shutdown Hysteresis THYST (Note 3) 20 NC *The parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.

Maxim Integrated Products 3 DS3920 Fast Current Mirror Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) GAIN ERROR vs. MIRIN VOLTAGE DS3920 toc06 VMIRIN (V) GAIN ERROR (%) 604020 -1.5 -1.0 -0.5 0.5 1.0 1.5 2.0 -2.0 0 80 IMIROUT = 2.5mA IMIROUT = 10mA IMIROUT = 1µA IMIROUT = 5mA GAIN ERROR vs. TEMPERATURE DS3920 toc05 TEMPERATURE (°C) GAIN ERROR (%) 603510-15 -40 85 IMIROUT = 2.5mA IMIROUT = 10mA IMIROUT = 1µA IMIROUT = 250µA VMIRIN = 40V GAIN ERROR vs. MIROUT CURRENT DS3920 toc04 IMIROUT (mA) GAIN ERROR (%) 10.10.01 0.001 10 VMIRIN = 40V MIRIN CURRENT vs. TEMPERATURE DS3920 toc03 TEMPERATURE (°C) IMIRIN (mA) 603510-15 0.1 0.01 -40 85 IMIROUT = 2.5mA IMIROUT = 1µA VMIRIN = 40V MIRIN CURRENT vs. MIROUT CURRENT DS3920 toc02 IMIROUT (mA) IMIRIN (mA) 10.10.01 0.1 100 0.01 0.001 10 VMIRIN = 40V MIRIN CURRENT vs. MIRIN VOLTAGE DS3920 toc01 VMIRIN (V) IMIRIN (mA) 604020 0.1 0.01 0 80 IMIROUT = 2.5mA IMIROUT = 1µA

Maxim Integrated Products 4 DS3920 Fast Current Mirror Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) STARTUP DELAY (VMIRIN = 5V, IMIROUT = 2.5mA) DS3920 toc11 200µs/div CH1 CH1: 2V/div CH2: 2V/div CH2 D.U.T MIRIN MIR MIROUT CH2 CH1 5kΩ 1.7kΩ STARTUP DELAY (VMIRIN = 5V, IMIROUT = 1µA) DS3920 toc10 200µs/div CH1 CH1: 2V/div CH2: 2V/div CH2 D.U.T MIRIN MIR MIROUT CH2 CH1 5kΩ 4.6MΩ STARTUP DELAY (VMIRIN = 40V, IMIROUT = 2.5mA) DS3920 toc09 200µs/div CH1 CH1: 20V/div CH2: 20V/div CH2 D.U.T MIRIN MIR MIROUT CH2 CH1 40V 5kΩ 15.6kΩ STARTUP DELAY (VBIAS = 40V, IMIROUT = 1µA) DS3920 toc08 200µs/div CH1 CH1: 20V/div CH2: 20V/div CH2 D.U.T MIRIN MIR MIROUT CH2 CH1 40V 5kΩ 38MΩ TRANSIENT RESPONSE (VMIRIN = 40V) DS3920 toc07 500ns/div A A: CH1, 1V/div, IMIROUT = 375µA TO 7.5mA A: CH2; 5V/div, IMIR = 75µA TO 1.5mA B D.U.T MIRIN MIR MIROUT CH2 CH1 40V 5kΩ 100kΩ 5kΩ

Maxim Integrated Products 5 DS3920 Fast Current Mirror Pin Configuration Pin Description Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) PIN NAME FUNCTION

1 DIODE

Protection Diode. External potential used for voltage clamping of VMIR. If unused, this pin can be left unconnected.

2 GND Ground

3 MIR Mirror Current Monitor Output, 5:1 Ratio

4 MIROUT

Current Mirror Voltage Output. Connect to photodiode bias pin. Photodiode provides reference current for the mirror. 5 N.C. No Connection. Not internally connected.

6 MIRIN Current Voltage Bias

3 MIROUT

6 MIRIN

5 N.C. DS3920 SHORT-CIRCUIT RESPONSE (VMIRIN = 40V) DS3920 toc12 20ms/div CH1 CH1: IMIROUT, 5mA/div A: MIROUT SHORTS TO GND THROUGH 10Ω B: CURRENT LIMIT ACTIVE C: THERMAL SHUTDOWN D: POST COOL-DOWN REENTRY E: THERMAL SHUTDOWN F: POST COOL-DOWN REENTRY TA = +40°C A B C D E F SHORT-CIRCUIT RESPONSE (VMIRIN = 76V) DS3920 toc13 20ms/div CH1 CH1: IMIROUT, 5mA/div A: MIROUT SHORTS TO GND THROUGH 10Ω B: CURRENT LIMIT ACTIVE C: THERMAL SHUTDOWN D: POST COOL-DOWN REENTRY E: THERMAL SHUTDOWN F: POST COOL-DOWN REENTRY TA = +40°C A B C D E F VOLTAGE DROP vs. MIROUT CURRENT DS3920 toc14 IMIROUT (mA) VMIRIN - VMIROUT (V) 1010.10.01 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0.001 100 VMIRIN = 2.97V TA = -40°C TA = +25°C TA = +100°C TA = +85°C

Maxim Integrated Products 6 DS3920 Fast Current Mirror Detailed Description The DS3920 provides a fast, precision current mirror for photodiode-monitoring applications. The current mirror is accurate across a large dynamic range. The mirror response time is fast enough to comply with GPON Rx burst-mode monitoring requirements. The device has a built-in current limiting feature to protect photodiodes from large signal inputs, and an included thermal shut - down. A diode is provided to limit the voltage at the MIR output. Current Mirror The mirror output is typically connected to an analog- to-digital converter (ADC) using a resistor to convert the mirrored current into a voltage. The resistor to ground should be selected so that the ADC’s full-scale voltage is reached when the maximum mirrored current is reached. For example, given that the maximum monitored current through the APD is 2mA, 1.25V ADC full scale, and a 5:1 mirror ratio, the correct resistor is approximately 3.2k I. The mirror response time is dominated by the amount of capacitance placed on the output. Current Clamp The device features a current clamping circuit to protect the photodiode by limiting the amount of current from MIROUT to no more than I MIROUT. See the Ordering Information for available current clamp options. Diode Protection A diode is internally connected from the MIR to DIODE pins. This enables an external voltage applied to DIODE to limit the voltage on MIR. The voltage applied to DIODE should be equal to the desired VMIR limit minus the diode forward voltage drop, or VMIR - VDF. Thermal Shutdown As a safety feature, the device has a thermal shutdown circuit that turns off the MIROUT and MIR currents when the internal die temperature exceeds TSHDN. The thermal shutdown mechanism has a built-in hysteresis of T HYST. Thus, the MIROUT and MIR currents resume once the device has cooled to TSHDN - THYST.

Ordering Information

+Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel.

Package Information

For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PART TEMP RANGE TYP CURRENT LIMIT (mA) PIN-PACKAGE DS3920T-001+ -40NC to +85NC 20 6 SOT23 DS3920T-001+T -40NC to +85NC 20 6 SOT23 DS3920T-002+ -40NC to +85NC 2.9 6 SOT23 DS3920T-002+T -40NC to +85NC 2.9 6 SOT23 PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

6 SOT23 U6SN+1 21-0058 90-0175

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 7 © 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. DS3920 Fast Current Mirror

Revision History

0 3/11 Initial release —