SC16458 led driver ic (10 x 4 segments) description SC16458 is an led controller driven on a 1/6 duty factor. it is suitable for most application in a lot of consumer products and is composed of one display memory, t en segment outputs, four grid outputs and control circuit. the microcomputer often needs this chip to build a highly reliable peripheral device. a three-line serial interface is used by SC16458 to get serial data. features * cmos technology * low power consumption * 8-step dimming circuitry * serial interface for clock, data input, strobe pins applications * microcomputer peripheral device sop-28-375-1.27 ordering informations device package SC16458 sop-28-375-1.27 block diagram absolute maximum ratings (unless otherwise stated, t amb =25 c, v ss =0v) characteristic symbol value unit supply voltage v dd -0.5 to +7 v logic input voltage v i -0.5 to v dd +0.5 v i olgr +250 ma driver output current i ohsg -50 ma hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 1 of 10
SC16458 electrical characteristics (unless otherwise stated, v dd =5v, v ss =0v, t amb =25 c) hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 2 of 10 note: test condition: set display contro l commands=80h (display turn off state) pin configurations 1 2 3 4 5 6 7 8 28 27 14 13 12 11 10 9 16 15 18 17 20 19 22 21 24 23 26 25 clk stb nc nc nc v dd seg1 seg2 seg3 seg4 seg5 seg6 seg7 seg8 nc seg9 seg10 nc nc g4 g3 g2 g1 nc v ss osc nc din SC16458 pin descriptions pin no. pin name description 1 clk clock input pin. this pin reads serial data at the rising edge. 2 stb serial interface strobe pin. the dat a input after the stb has fallen is processed as a command. when this pin is ?high?, clk is ignored. 3~5, 15, 18, 19, 24, 27 nc no connection 6 v dd logic power supply 7~14, 16~17 seg1 ~ seg8, seg9~seg10 segment output pins (p-channel, open drain) 20~23 g4 to g1 grid output pins (n-channel, open drain) 25 v ss ground 26 osc oscillator input pin. this pin requires a resistor to obtain the accurate oscillation frequency. 28 din data input pin. this pin inputs serial data at the rising edge of the shift clock (starting from the lower bits). characteristics symbol test condition min. typ. max. unit logic supply voltage v dd 4.5 5 5.5 v dynamic current (note) i dddyn -- -- 5 ma i ohsg1 v o =v dd -1v seg1 to seg10 -10 -14 -- ma high-level output current i ohsg2 v o =v dd -2v seg1 to seg10 -20 -25 -- ma low-level output current i olgr v o =0.3v, g1 to g5 100 140 -- ma segment high-level output current tolerance i tolsg v o =v dd -1v seg1 to seg10 -- -- 5 % high-level input voltage v ih -- 0.7v dd -- 5 v low-level input voltage v il -- 0 -- 0.3v dd v oscillation frequency fosc r=51k 350 500 650 khz
SC16458 function descriptions commands after the stb pin changes from ?high? to ?low?, SC16458g will obtain a command via the din pin. otherwise, the stb pin is set to ?high?, the data/co mmands being transmitted are considered invalid and the communication is initialized. command 1: data setting commands the data setting commands executes the data write or data read modes for SC16458g. the data setting command, the bit 5 and bit 6 (b4, b5) are ignored, bit 7 (b6) is given the value of ?1? while bit 8(b7) is set the value ?0?. please refer to the diagram below. when power is on, bit 4 to bit 1 (b3 to b0) are set the value of ?0?. 0 - - b3b2b1b0 1 data write & read mode settings: 00: write data to display mode not relevant msb lsb address increment mode settings (display mode): 0: increment address after data has been written (see note 1) 1: fixes address mode settings: 0: normal operation mode 1: test mode note: 1. if you want to set bit 3 (b2) to ?0?, pleas e remember that dig5 address cannot be ignored since g5 exists, however, it is not exter nally bonded. please refer to command 2, display mode and ram address section. command 2: address setting commands the address of the display memory is set by address setti ng commands. if the address has a value of ?00h? to ?09h?, it is considered valid. if the address is set to 0ah or higher, the data is ignored until a valid address is set. when power is turned on, the address is set at ?00h?. please refer to the diagram below. 1 - - b3b2b1b0 1 address: 00h to 09h not relevant msb lsb display mode and ram address when an external device transmits the serial data into SC16458g, this data is stored in the display ram and is assigned addresses. the ram addresses of SC16458g are given below in 8-bit unit. hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 3 of 10
SC16458 seg1 seg4 seg5 seg8 seg9 seg10 00hl 00hu 01hl dig1 02hl 02hu 03hl dig2 04hl 04hu 05hl dig3 06hl 06hu 07hl dig4 08hl 08hu 09hl dig5 b0 b3 b4 b7 xxhl xxhu lower 4 bits higher 4 bits command 3: display control commands. the display control commands are used to turn on or off a display. it also used to set the pulse width. please refer to the diagram below. a 1/16 pulse width is selected and the display is turned off only when the power is turned on. 1 - - b3b2b1b0 0 hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 4 of 10 dimming quantity settings: 000: pulse width = 1/16 001: pulse width = 2/16 010: pulse width = 4/16 011: pulse width = 10/16 100: pulse width = 11/16 101: pulse width = 12/16 110: pulse width = 13/16 111: pulse width = 14/16 not relevant msb lsb display setings: 0: display off 1: display on serial communication format the following diagram shows the SC16458g serial communication format. reception (data/command write) probably data will continue stb din clk 123 78 b0 b1 b2 b6 b7
SC16458 switching characteristic waveform SC16458g switching characteristics waveform is given below. fosc 50% osc stb clk din gn pw clk pw clk t clk-str t setup t hold pw stb ttlz ttzl 90% 10% sn ttzh tthz 10% 90% where: pwclk (clock pulse width) 400ns pwstb (strobe pulse width) 1 s t setup (data setup time) 100ns t hold (data hold time) 100ns t clk-stb (clock strobe time) 1 s t thz (fall time) 10 s t tzh (rise time) 1 s f osc = oscillation frequency t tzl <1 s t tlz <10 s hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 5 of 10
SC16458 applications display memory is update by incrementing addresses. please refer to the following diagram. stb clk din command1 command2 data 1 data n command3 where: only when "stb" is low , the "clk" signal is valid. command 1: data setting command command 2: address setting command data 1 to n: transfer display data (10 bytes max.) command 3: display control command the following diagram shows the waveforms when updating specific addresses. stb clk din command1 command2 data where: only when "stb" is low , the "clk" signal is valid. command 1--data setting command command 2-- address setting command data-- display data command2 data hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 6 of 10
SC16458 recommended programming flowchart set data start set address clear display ram (see note) hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 7 of 10 set display display on ("10xx1xxx") main program set data set address set display display on ("10xx1xxx") initial setting main loop end note: when ic power is applied for th e first time, the contents of the di splay ram are not defined; thus, it is strongly suggested that the contents of the display ram must be cleared during the initial setting.
SC16458 typical application circuit 0.1 f hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 8 of 10 1 2 3 4 5 6 7 8 28 27 14 13 12 11 10 9 16 15 18 17 20 19 22 21 24 23 26 25 clk stb nc nc nc v dd seg1 seg2 seg3 seg4 seg5 seg6 seg7 seg8 nc seg9 seg10 nc nc g4 g3 g2 g1 nc v ss osc nc din SC16458 mcu s1 s2 s3 s4 s5 s6 s7 s8 s10 s9 g1 g2 g3 g4 51k +5v seg4 seg5 seg6 seg7 seg8 seg9 seg10 4-grid x 10-segmentnt led common cathode s5 s6 s7 s8 s9 s10 digit1 digit2 digit3 digit4 seg1 seg2 seg3 s1 s2 s3 s4 g1 g2 g3 g4 note: the capacitor (0.1 f) connected between the gnd and v dd pins must be located as near as possible to the SC16458 chip. seg1 seg2 seg3 seg4 seg5 seg6 seg7 seg8 a b c d e f g h com / digital (grid) a b c d e f g h
SC16458 package outline sop-28-375-1.27 unit: mm hangzhou silan microelectronics co.,ltd rev:1.2 2004.8.31 http: www.silan.com.cn page 9 of 10 17.75 0.25 16.51 0.45 0.15 0.05 1.27 handling mos devices: electrostatic charges can exist in many things. all of our mos devices are inte rnally protected against electrostatic discharge but they can be damage d if the following precautions are not taken: ? persons at a work bench should be earthed via a wrist strap. ? equipment cases should be earthed. ? ? all tools used during assembly, including sol dering tools and solder baths, must be earthed. ? mos devices should be packed for dispatch in antistatic/conductive containers.
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