Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX3806GTC+

General Description

The MAX3806 is a high-gain linear preamplifier for dis-

tance measurement applications using a laser beam.

The device operates from a single +5.0V supply and

converts current from an AC-coupled photodiode into a

single-ended voltage signal. The input accepts single

pulses or bursts of pulses with widths down to 30ns. The

amplifier remains linear with input amplitudes from 42nA

(SNR = 3) to 40μA

. It can also withstand overload sig-

nals as large as 2mA

. The output stage is designed to

drive a high-impedance load to deliver the output-voltage

swing at the lowest possible power dissipation. The gain

of the preamplifier stage is selected using the GAIN pin to

be 60kΩ or 30kΩ. There is also an internal 14dB attenu-

ator that is selected using the ATT pin. The output stage

can be disabled (high impedance).

The device is available in a 3mm x 3mm, 12-pin TQFN

package and operates over the -40°C to +105°C tem-

perature range.

Applications

● LIDAR Sensors for Automotive Applications

(ACC, Stop&Go)

● Laser Sensors for Portable Distance Measurement

● Laser Sensors for Industrial Applications

Benets and Features

● +5V Supply Voltage

● Linearity Range Up to 40μA

● Overload Current Up to 2mA

● 50mW Power Dissipation at +5.0V

● 1.5pA/√Hz Noise Density at 60kΩ Gain

● 14nA

RMS

Input-Referred Noise at 60kΩ Gain

● Selectable Gains (60kΩ, 30kΩ)

● Selectable 14dB Attenuation

Typical Application Circuits continued at end of data sheet.

Pin Configuration appears at end of data sheet.

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

PART TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX3806GTC+ -40°C to +105°C 12 TQFN-EP* ABN

+5V

SINGLE-CHANNEL RECEIVER

* L AND C SET THE LOW-FREQUENCY CUTOFF REQUIRED FOR THE APPLICATION.

+5V

OUT

BUFF

GAIN

0.01µF

MAX3806

LINEAR LIDAR Rx

MAX1446

ADC

SUPPLY FILTER

GNDATTDIS

+5V TO +12V

SUPPLY FILTER

MAX3806 Receiver for Optical Distance Measurement

19-4700; Rev 1; 6/14

Typical Application Circuits

Ordering Information

EVALUATION KIT AVAILABLE

Summary of content (10 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX3806 Receiver for Optical Distance Measurement General Description Benefits and Features The MAX3806 is a high-gain linear preamplifier for distance measurement applications using a laser beam. ●● +5V Supply Voltage ●● Linearity Range Up to 40μAP ●● Overload Current Up to 2mAP The device operates from a single +5.0V supply and converts current from an AC-coupled photodiode into a single-ended voltage signal.
PAGE 2
MAX3806 Receiver for Optical Distance Measurement Absolute Maximum Ratings Supply Voltage Range, VCC...................................-0.5V to +6.0V Voltage Range at ATT, DIS, GAIN...............-0.5V to (VCC + 0.5V) Current Range at IN, OUT.......................................-4mA to +4mA Continuous Power Dissipation (TA = +70°C) 12-Pin TQFN-EP (derate 16.7mW/°C above +70°C)...1333mW Storage Temperature Range .............................-55°C to +150°C Lead Temperature (soldering, 10s) .............
PAGE 3
MAX3806 Receiver for Optical Distance Measurement Electrical Characteristics (continued) (VCC = +4.5V to +5.5V, AC-coupled (C = 0.01μF) output load ≥ 2kΩ, TA = -40°C to +105°C. Typical values are at VCC = +5V, TA = +25°C, unless otherwise noted.
PAGE 4
MAX3806 Receiver for Optical Distance Measurement Typical Operating Characteristics (continued) (Typical values are at VCC = +5V, TA = +25°C, CIN = 5pF, ATT = 0, unless otherwise noted.) 20 TA = +105 NC 7 9 11 13 MAX3806 toc06 MAX3806 toc05 20 0.6 GAIN = 0 0.4 VCC = +4.5V 0.2 GAIN = 1 5 7 9 11 13 0 15 7 5 9 11 13 15 BANDWIDTH vs. INPUT CAPACITANCE (GAIN = 0) BANDWIDTH vs.
PAGE 5
MAX3806 Receiver for Optical Distance Measurement Typical Operating Characteristics (continued) (Typical values are at VCC = +5V, TA = +25°C, CIN = 5pF, ATT = 0, unless otherwise noted.) 23 TA = +25°C 22 21 20 TA = -40°C 19 18 5 7 9 11 13 TA = +25°C 25 VCC = +5.5V 24 23 VCC = +5.0V 22 21 VCC = +4.5V 20 19 18 15 GAIN = 0 BW = 100MHz 5 INPUT CAPACITANCE (pF) 7 9 11 13 15 INPUT CAPACITANCE (pF) 700 TA = +25°C 650 GAIN = 0 BW = 100MHz VCC = +5.5V VCC = +5.
PAGE 6
MAX3806 Receiver for Optical Distance Measurement Typical Operating Characteristics (continued) (Typical values are at VCC = +5V, TA = +25°C, CIN = 5pF, ATT = 0, unless otherwise noted.) TRANSIENT RESPONSE (LINEAR REGION, GAIN = 1) TRANSIENT RESPONSE (OVERLOAD REGION, GAIN = 1) MAX3806 toc20 TRANSIENT RESPONSE (OVERLOAD REGION, GAIN = 1) MAX3806 toc21 MAX3806 toc22 ZOOM IN 1µAP ZOOM OUT 2mAP IN OUT 2mAP IN IN OUT OUT 60mVP 1.4VP 60µs SETTLING TIME 1.4VP 20MHz BW LIMIT 0.
PAGE 7
MAX3806 Receiver for Optical Distance Measurement Pin Description PIN NAME 1, 12 VCC FUNCTION 2 IN 3, 4 GND Supply Ground 5 ATT CMOS/TTL Input. Assert this pin high to enable a 14dB attenuator in the amplifier. Force this pin low to disable the attenuator. Contains internal 40kΩ pulldown resistor. Connect to GND if not used. 6, 8, 11 N.C. Not Connected. This pin is not internally connected. 7 GAIN CMOS/TTL Input. Selects amplifier gain setting. Force high for 60kΩ. Force low for 30kΩ.
PAGE 8
MAX3806 Receiver for Optical Distance Measurement Layout Considerations VCC Noise performance and bandwidth are adversely affected by capacitance at the IN pad. Minimize capacitance on this pad and select a low-capacitance photodiode. Reducing PCB capacitance can be accomplished by removing the ground plane underneath the connection from the photodiode to the IN pin and by keeping the photodiode as close as possible to the MAX3806.
PAGE 9
MAX3806 Receiver for Optical Distance Measurement Typical Application Circuits (continued) +5V +5V TO +12V SUPPLY FILTER SUPPLY FILTER VCC +5V PIN MAX3806 IN LINEAR LIDAR Rx C* 7kΩ 0.01F OUT 3kΩ L* GAIN DIS ATT GND +5V MULTIPLE-CHANNEL RECEIVER DIS0 +5V +5V TO +12V SUPPLY FILTER SUPPLY FILTER VCC +5V PIN MAX3806 IN LINEAR LIDAR Rx C* 7kΩ 0.01F 3kΩ L* GAIN DIS ATT +5V OUT GND +5V MAX4311 4:1 MUX/AMP IN0 DIS1 0.01F 0.
PAGE 10
MAX3806 Receiver for Optical Distance Measurement Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 7/09 Initial release 1 6/14 Removed automotive reference from Applications section and corrected page code DESCRIPTION — 1, 8 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.