HBCC-0500

HBCC-0500 HP | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 4

Technical content

Features

• Compatible with HP Bar Code Sensors – HBCC-1570 - 0.013 in. 0.33 mm - HBCC-1580 - 0.007 in. 0.185 mm - HBCC-1590 - 0.005 in. 0.13 mm
• Ambient Light Rejection > 100 K Lux
• Accurate Digitizing of a Wide Range of Bar Code Labels

Description

The Hewlett-Packard Low Current Bar Code Digitizer IC allows designers to incorporate the high ambient light rejection and low power consumption features of the HBCS-AXXX/TXXX wands into their own bar code circuitry. The HBCC-0500 is packaged in a 24 pin SOIC plastic package. Theory of Operation The digitizer IC uses the tech- niques in US Patent 4,682,015 to reduce power consumption and sensitivity to ambient light. Power is reduced by pulsing the LED every 33 microseconds with a 1 microsecond pulse. The output of different sensor “bins” is equalized by varying the amplitude of the LED drive current. The sensor output has two com- ponents; DC due to ambient light, and AC from the bar code label. Photocurrent from the sensor is amplified and high pass filtered to remove the ambient light signal. The AC component is amplified and sent to an AM detector to recover the bar code information. The recovered bar code signal is low pass filtered to eliminate the 30 kHz carrier. The signal is input to a digitizer consisting of positive and negative Block Diagram SENSOR LED DRIVER AMPLIFIER HIGH PASS FILTER AMPLIFIER AM DETECTOR LOW PASS FILTER DIGITIZER OUTPUT peak detectors and a comparator. The comparator threshold is generated from the peak detectors using a resistor ladder. This threshold, along with the current bar code signal, is input to a comparator. The output of the comparator drives an external output transistor.

PPKD Positive Peak Detector PRBP Preamp Bias Point PSTB Postamp Bypass ACMP Compensation Cap AMDT AM Detector CMPA Compensation Cap PSTI Postamp Input NPKD Negative Peak Detector CMPI Comparator Input CTHR Comparator Threshold CMPO Comparator Output IWSR White State Return Current LPFI Low Pass Filter Input LPFO Low Pass Filter Output GND Ground LEDD LED Drive Bin Table Bin # 1570, 1580 Rb Ω 1590 Rb Ω 1 8.2 22 21 12 7 31 53 6 41 84 7 52 45 6 63 07 5 73 69 1 RPER 1 RPWD 2 CTIM 3 VCC 4 AGND 5 EMIN 6 PREO 7 VCC A8 PPKD 9 PRBP 10 PSTB 11 ACMP 12 LEDD GND LPFO LPFI IWSR CMPO CTHR CMPI NPKD PSTI CMPA AMDT HBCC-0500 Sensor Pinout TOP VIEW 2 6 3 5 1 7 Function Pin # LED Anode 6 LED Cathode 2 Detector Anode 8 Detector Cathode 1 Sensor Marking Sensors are marked with an eight digit code, the last digit being the “bin” number. The bin number is used to determine the bin resistor, Rb, using the Bin Table. Parts List Quantity Part

1 Sensor

1 HBCC-0500

2 39 Ω 1 9.1 k Ω 2 20 k Ω 2 56 k Ω 1 390 k Ω 2 470 k Ω 1 680 k Ω 1 1.3 M Ω 1 2.0 M Ω 2 6.8 M Ω

1 Bin resistor R b

2 1.0 nF 1 2.2 nF 1 8.2 nF 4 0.1 µF 3 0.22 µF 1 0.47 µF Optional Parts List Quantity Part 1 1N4148 1 2N5088 1 2N3904 2 10 k Ω 1 220 k Ω 1 1.0 M Ω 1 2.0 M Ω 1 3.3 nF 1 1.0 µF

schematic for the HBCC-0500. Here are some construction tips. 1. Place the sensor, 2N4403, bin resistor, and the 0.47 µF cap close to each other to minimize loop area. 2. If the 0.47 µF cap is tantalum, its ESR must be used in series with R b to determine the correct value for Rb. 3. A 1.0 µF ceramic cap may be used in place of the 0.47 µF cap. 4. Place the 0.22 µF cap attached to pins 4 and 23 close to the IC. 5. Use a single point ground close to pin 23. Options There are four options on the recommended schematic. 1. Output pull up resistor 2. Inverted output 3. Black state return 4. Threshold adjust Pull Up Resistor The 10 kΩ pull up resistor on the standard or inverted output transistor is optional. If the transistor is driving a cable, the resistor should be on the far end of the cable. Schematic LEDD VCC GND PSTI PREO EMIN AGND RPER RPWD CTIM PPKD CMPO CMPI LPFO AMDT LPFI CMPA ACMP IWSR VCC A PRBP PSTB NPKD 2.2 nF

56 KΩ 56 KΩ

2.0 MΩ 20 KΩ 680 pF 1.3 MΩ 2.0 MΩ 220 KΩ 1.0 MΩ 1.0 pF2N5088 1N4148 +5 V 3.3 nF +5 V +5 V

390 KΩ470 KΩ

0.22 µF 0.1 µF 0.1 µF 0.1 µF 39 Ω39 Ω R b Ω 0.22 µF 0.22 µF 0.47 µF 8.2 nF 680 KΩ 470 KΩ 9.1 KΩ 2N5088 75 pF 0.1 µF

6.8 MΩ+5 V

(OPTIONAL) 10 KΩ (OPTIONAL) INVERTED OUTPUT INVERTED OUTPUT (OPTIONAL) 2N3904

10 KΩ (OPTIONAL)

20 KΩ CTHR +5 V

Electrical Characteristics

Parameter Symbol Typical Max. Units Notes Supply Current, IC and Sensor I CC 2.7 4.0 mA High Level Output Current I OH 1.0 µA Low Level Output Voltage V OL 0.4 V Output Rise Time t r 4.5 20 µs4 Output Fall Time t f 0.3 20 µs4 Wake Up Time t w 50 200 ms 5 Notes: 4. Rise and fall time will be dependent upon the capacitance of the cable. 5. Wake up time is defined as the time from initial power turn on until the circuit is digitizing bar codes within data sheet limits. Inverted Output The standard output of the HBCC-0500 is high when the sensor is looking at black bars, and low when the sensor is look- ing at white spaces. If inverted output is needed, add the extra circuitry in the inverted output block. Make sure that the 10 kΩ pull up resistor on the normal output transistor is loaded. Black State Return The HBCC-0500 normally returns to the white state 100 millisec- onds after the last transition. The extra circuitry forces the black state after a time out period set by the 1.0 µF cap. The normal time out period is about 1.5 sec- onds. If a longer time is needed, increase the values of the 1.0 µF and the 3.3 nF caps. The ratio of values should be no more than 300:1. Threshold Adjustment The standard circuit uses a threshold designed for most bar codes. If the bar codes to be read consistently have narrow bars that are lighter than the wide bars, then the 470 kΩ and the 390 kΩ resistors attached to pin 18 should be swapped. Warranty and Service HP Digitizer ICs are warranted for a period of one year after purchase covering defects in material and workmanship. Hewlett-Packard will repair or, at its option, replace products that prove to be defective in material or workmanship under proper use during the warranty period. NO OTHER WARRANTIES ARE EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. HEWLETT-PACKARD IS NOT LIABLE FOR CONSEQUENTIAL DAMAGES. For additional warranty or service information, please contact your local Hewlett-Packard sales representative or authorized distributor. Recommended Operating Conditions Parameter Min. Max. Units Notes Scan Velocity 7.6 (3) 76 (30) cm/sec (in/sec) 1 Edge Contrast 40 % 2 VCC 4.5 6.0 V 3 Ambient Temperature -20 +65 °C Ambient Light 100,000 Lux Notes: 2. Contrast is defined as R w - Rb, where Rw is the reflectance of the spaces in R b is the reflectance of the bars, measured at the sensor wavelength (655 or 820 nm). 100% reflectance is barium sulfate. 3. Power supply ripple and noise should be less than 100 mV peak to peak.