mxb7843 Maxim Integrated Products, Inc., mxb7843 Datasheet
mxb7843
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mxb7843 Summary of contents
Page 1
... The MXB7843 has two auxiliary ADC inputs. All analog inputs are fully ESD protected, eliminating the need for external TransZorb™ devices. The MXB7843 is guaranteed to operate with a single 2.375V to 5.25V supply voltage. In shutdown mode, the typical power consumption is reduced to under 0.5µW, while the typical power consumption at 125ksps throughput and a 2.7V supply is 650µ ...
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Touch-Screen Controller ABSOLUTE MAXIMUM RATINGS CS, DCLK to GND ...................................-0. DIN, DD Digital Outputs to GND...............................-0. X+, X-, Y+, Y-, IN3, IN4 to GND........-0. REF Maximum ...
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Touch-Screen ELECTRICAL CHARACTERISTICS (continued 2.7V to 3.6V 2.5V REF DCLK unless otherwise noted. Typical values are at T MIN MAX PARAMETER SYM REFERENCE ...
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Touch-Screen Controller TIMING CHARACTERISTICS (Figure 2.7V to 3.6V 2.5V REF DCLK unless otherwise noted. Typical values are at T MIN MAX PARAMETER SYM B O ...
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Touch-Screen (V = 2.7V 2.5V 2MHz REF DCLK noted.) INTEGRAL NONLINEARITY vs. DIGITAL OUTPUT CODE 0.5 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 0 500 1000 1500 2000 ...
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Touch-Screen Controller (V = 2.7V 2.5V 2MHz REF DCLK noted.) REFERENCE CURRENT vs. SUPPLY VOLTAGE 8 0.1µ 125kHz SAMPLE 8.2 8.1 8.0 7.9 7.8 7.7 ...
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Touch-Screen PIN NAME 1 V Positive Supply Voltage. Connect to pin 10 Position Input, ADC Input Channel Position Input, ADC Input Channel Position Input ...
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... It features a 4-wire touch-screen interface and two auxiliary ADC channels (Functional Diagram). Figure 2 shows a block diagram of the analog input sec- tion that includes the input multiplexer of the MXB7843, the differential signal inputs of the ADC, and the differ- ential reference inputs of the ADC. The input multiplexer switches between X+, X-, Y+, Y-, IN3, and IN4 ...
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Touch-Screen IN3 IN4 REF Table 1. Input Configuration, Single-Ended Reference Mode (SER/DFR HIGH MEASUREMENT ...
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... The PENIRQ output can be used to initiate an interrupt to the microprocessor, which can write a control word to the MXB7843 to start a conversion. Figure 6 shows the timing diagram for the PENIRQ pin function. The diagram shows that once the screen is ...
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Touch-Screen IN3 IN4 GND Figure 2. Equivalent Input Circuit GND Figure 3. Single-Ended Y-Coordinate Measurement ______________________________________________________________________________________ PENIRQ V REF DD A2–A0 (SHOWN 001 ) B SER/DFR (SHOWN ...
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Touch-Screen Controller TOUCH SCREEN PENIRQ Functional Block Diagram Figure 5. SCREEN TOUCHED HERE PENIRQ CS DCLK DIN INTERRUPT PROCESSOR NO RESPONSE TO TOUCHMASK PENIRQ t TOUCH Figure 6. PENIRQ ...
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... START bit (Figure 8). Once a start bit has been recognized, the current con- version must be completed. The fastest the MXB7843 can run with CS held continu- ously low is 15 clock conversions. Figure 8 shows the serial-interface timing necessary to perform a conver- sion every 15 DCLK cycles connected low and DCLK is continuous, guarantee a start bit by first clock- ing in 16 zeros ...
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... The faster clock rate and fewer clock cycles combine to increase the conversion rate. The MXB7843 output data is in straight binary format as shown in Figure 10. This figure shows the ideal output code for the given input voltage and does not include the effects of offset, gain, or noise ...
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Touch-Screen DCLK DIN S CONTROL BYTE 0 DOUT BUSY Figure 9. 16-Clock/Conversion Timing Table 3. Control Byte Format BIT 7 BIT 6 BIT 5 START A2 A1 BIT NAME 7 START Start bit ...
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... Power Modes conversion completes or on the next rising edge of CS, whichever occurs first. The next control byte received on DIN powers up the MXB7843. At the start of a new con- version, it instantly powers up. When each conversion is finished, the part enters power-down mode, unless other- wise indicated ...
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... The TMS320 reads in 1 data bit on each of the next 16 rising edges of DCLK. These bits represent the 12-bit conversion result followed by 4 trailing bits. 6) Pull CS high to disable the MXB7843 until the next conversion is initiated. For best performance, use printed circuit (PC) boards with good layouts; wire-wrap boards are not recommend- ed ...
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... MXB7843 Figure 12. QSPI/SPI Interface TMS320LC3x Figure 13. TMS320 Serial Interface static linearity parameters for the MXB7843 are mea- sured using the end-point method. Differential nonlinearity (DNL) is the difference between an actual step width and the ideal value of 1LSB. A DNL error specification of less than 1LSB guarantees no missing codes and a monotonic transfer function ...
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... Touch-Screen CS DCLK DIN START BUSY DOUT Figure 14. MXB7843-to-TMS320 Serial Interface Timing Diagram 2.375V TO 5.5V 1µF TO 10µF OPTIONAL TOUCH SCREEN ______________________________________________________________________________________ MODE SER/DEF PD1 PD0 MSB 0.1µ DCLK DIN 4 MXB7843 X- BUSY 5 Y- ...
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Touch-Screen Controller (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) 20 ______________________________________________________________________________________ Package Information PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH ...
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... 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 ____________________ 21 © 2005 Maxim Integrated Products Package Information (continued) Printed USA is a registered trademark of Maxim Integrated Products, Inc. Controller PACKAGE OUTLINE, TSSOP 4.40mm BODY 1 21-0066 ...