NTE1503 Integrated Circuit 5–Step LED Driver Circuit for Logarithmic Response Description: The NTE1503 is an integrated circuit in a 9–Lead SIP type package designed for driving 5–LED bar graphs or dot displays so that the LEDs may light logarithmically (dB) for input signal. Brightness of the LEDs can be controlled by using the output current adjustment pin provided. Features: D 5–LED Bar Graph or Dot Display Drive D Logarithmic Response with Respect to Input D Brightness Externally Adjustable D High Output Current, Suitable for Green LED Drive D Lamp ON/OFF Hysteresis, No Flickering by Noise Absolute Maximum Ratings: (TA = +25°C unless otherwise specified) Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +18V Circuit Voltage, V8–5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +16V Load Current Set Input Voltage, V7–5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +16V Output Voltage (Note 1), VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5V to +16V Supply Current, ICC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18mA Load Current Set Input Current, I7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.25mA Output Current, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA Power Dissipation, PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550mW Operating Ambient Temperature Range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –20° to +75°C Storage Temperatuere Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55° to +150°C Note 1. Output Pin1, Pin2, Pin3, Pin4, and Pin6. Electrical Characteristics: (TA = +25°C, VCC = 16V unless otherwise specified) Parameter Min Typ Max Unit VI(ON)1 – – 1.12 V LED 2 VI(ON)2 – – 1.86 V LED 3 VI(ON)3 – – 3.10 V LED 4 VI(ON)4 – – 5.18 V LED 5 VI(ON)5 – – 8.66 V Input Voltage (LED ON) LED 1 Symbol Test Conditions Electrical Characteristics (Cont’d): (TA = +25°C, VCC = 16V unless otherwise specified) Parameter Symbol Min Typ Max Unit VI(OFF)1 0.80 – – V LED 2 VI(OFF)2 1.49 – – V LED 3 VI(OFF)3 2.54 – – V LED 4 VI(OFF)4 4.28 – – V LED 5 VI(OFF)5 7.23 – – V Load Current Pin6 I6 VO = 1.2V, I7 = 4.25mA 13 16 – mA I1 to I4 VO = 2.5V, I7 = 4.25mA 13 16 – mA I1 to I4, I6 VO = 16V, I7 = 4.25mA – 16 19 mA V8–5 = 8.7V – – 50 µA V8–5 = 16V – – 5 mA V8–5 = 16V – – 18 mA VO = 16V – – 15 µA Input Voltage (LED OFF) LED 1 Pin1 to Pin4 Pin1 to Pin4, Pin6 Input Current I8 Supply Current I9 Output Pin Leakage Current I1 to I4, I6 Test Conditions Pin Connection Diagram (Front View) 9 8 7 6 5 4 3 2 1 .929 (23.6) VCC Input Output Current Adjust LED 5 GND LED 4 LED 3 LED 2 LED 1 .118 (3.0) .236 (6.0) 1 9 .098 (2.5) .100 (2.54) .118(3.0)