TS809/ 810/ 809R/ 810R Microprocessor Reset Circuit Pin assignment: TS809/810 1. Gnd 2. RESET (RESET) 3. Vcc Threshold Voltage Option From 2.63V ~ 4.63V Pin assignment: TS809R/810R 1. RESET (RESET) 2. Gnd 3. Vcc General Description The TS809/810/809R/810R are microprocessor (µP) supervisory circuit used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 240ms(typ) after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The TS809/810/809R/810R have push pull outputs. The TS809/809R have an active low RESET output, while the TS810/810R has an active high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the output guaranteed to be in the correct logic state for VCC down to 1V. Low supply correct makes the TS809/810/809R/810R ideal for use in portable equipment. The TS809/810/809R/810R is available in a 3-pin SOT-23 package. Features Ordering Information Part No. Precision monitoring of +3V, +3.3V and +5V Enable Function power supply voltage TS809CX x Active-Low Fully specified over temperature TS810CX x Active-High Available in three output configurations TS809RCXx Active-Low TS810RCXx Active-High Push-Pull RESET low output (TS809 & TS809R) Push-Pull RESET high output (TS810 & TS810R) 140mS min. power-on reset pulse width 12uA supply current Guaranteed reset valid to Vcc = +1V Power supply transient immunity No external components Note: x is the threshold voltage type, option as A: 4.63V B: 4.38V C: 4.00V D: 3.08V E: 2.93V F: 2.63V Pin Descriptions Applications Computers Name Controllers Gnd Intelligent instruments Ground Reset output pin Critical uP and uC power monitoring RESET Portable / Battery powered equipment (RESET) Automotive TS809/810/809R/810R Description Vcc 1-6 L: for TS809 & TS811 H: for TS809R & TS811R Operating voltage input 2004/09 rev. D Package SOT-23 Absolute Maximum Rating Terminal Voltage (with respect to Gnd) RESET & (RESET) push-pull VCC - 0.3 ~ +6.0 V VRESET - 0.3 ~ (VCC +0.3) V ICC 20 mA IO 20 mA PD 320 mW TOP -40 ~ +105 o C TSTG -65 ~ +150 o C TLEAD 10 Input Current, Vcc Output Current, RESET, (RESET) o Continuous Power Dissipation (Ta=+70 C) o o de-rate 4mW/ C above +70 C Operating Junction Temperature Range Storage Temperature Range o Lead Soldering Temperature (260 C) S Electrical Characteristics (Ta = 25 oC, unless otherwise specified.) Parameter Conditions o o Symbol Min Typ Max Unit Input Supply Voltage Ta = 0 C ~ +70 C VCC 1.0 -- 5.5 V Supply Current VCC ≤ 5.5V ICC -- 19 60 uA - 17 50 4.56 4.63 4.7 4.31 4.38 4.45 3.94 4.00 4.06 TS809/910/809R/810RCXD 3.03 3.08 3.13 TS809/910/809R/810RCXE 2.89 2.93 2.97 TS809/910/809R/810RCXF 2.59 2.63 2.67 -- 30 -- VCC ≤ 3.6V TS809/910/809R/810RCXA TS809/910/809R/810RCXB Reset Threshold TS809/910/809R/810RCXC Reset Threshold VTH VTH o o Vcc Rising Time to Function Ta = -20 C ~ +105 C VCC to Reset Delay VCC = VTH to (VTH - 100mV) o 25 Ta = 0 C ~ +70 C RESET Output Voltage High TS809 & TS809R 20 100 uS 100 240 600 mS -- -- 0.3 V -- -- 0.4 VCC > 1.0V, ISINK =50uA -- -- 0.3 0.8 VCC -- -- VOH VCC > VTH(MAX), ISOURCE =800uA, VCC = VTH(MAX), ISINK =1.2mA, TS810 & TS810R 1.8V < VCC < VTH(MIN), V VCC –1.5 -- -- -- -- 0.3 VOL VCC = VTH(MAX), ISINK =3.2mA, RESET Output Voltage High uS/V VCC = VTH(MIN), ISINK =3.2mA, TS809 & TS809R RESET Output Voltage Low -- VOL VCC > VTH(MAX), ISOURCE =500uA, VOH V -- -- 0.4 0.8 VCC -- -- ISOURCE =150uA, TS810 & TS810R TS809/810/809R/810R 2-6 C -- TDELAY o VCC = VTH(MIN), ISINK =1.2mA, RESET Output Voltage Low ppm/ o Temperature Coefficient Reset Active Timeout Period V 2004/09 rev. D V Application Note Function Description A microprocessor’s (µP’s) reset input starts the µP In a know state. The TS809/810/809R/810R assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions. They assert a reset signal whenever the Vcc supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after Vcc has risen above the reset threshold. The TS809/810/809R/810R have a push-pull output stage. Applications Information Negative-Going VCC transients in addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the TS809/810/809R/810R are relatively immune to short-duration negative-going Vcc transients (glitches). The TS809/810/809R/810R do not generate a reset pulse. The graph was generated using a negative going pulse applied to Vcc, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse width a negative going Vcc transient can have without causing a reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, a Vcc transient that goes 100mV below the reset threshold and lasts 20µS or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the Vcc pin provides additional transient immunity. Ensuring a Valid Reset Output Down to Vcc=0 When Vcc falls below 1V, the TS809/810/809R/810R RESET output no longer sinks current - it becomes an open circuit. Therefore, high impedance CMOS logic input connected to RESET can drift to undetermined voltages. This present no problem in most applications since most µP and other circuitry is inoperative with Vcc below 1V.However, in applications where RESET must be valid down to 0V, adding a pull down resistor to RESET causes and stray leakage currents to flow to ground, holding RESET low (Figure 2.) R1’s value is not critical; 100K is large enough not to load RESET and small enough to pull RESET to ground. For the TS809/810/809R/810R if RESET is required to remain valid for Vcc<1V. Benefits of Highly Accurate Reset Threshold Most µP supervisor ICs have reset threshold voltages between 5% and 10% below the value of nominal supply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset many or may not be asserted. Timing Diagram Applications Circuit TS809/810/809R/810R 3-6 2004/09 rev. D Electrical Characteristics Curve Figure 1. Iq v.s. Temperature Figure 2. Threshold v.s. Temperature Figure 3. Immunity TS809/810/809R/810R 4-6 2004/09 rev. D Function Block Marking Information Part No. Identification Part No. Code Identification Part No. Code Identification Part No. Code Identification Code TS809CXA EA TS810CXA E0 TS809RCXA EG TS810RCXA E7 TS809CXB EB TS810CXB E2 TS809RCXB EH TS810RCXB E8 TS809CXC EC TS810CXC E3 TS809RCXC EI TS810RCXC E9 TS809CXD ED TS810CXD E4 TS809RCXD EJ TS810RCXD EM TS809CXE EE TS810CXE E5 TS809RCXE EK TS810RCXE EN TS809CXF EF TS810CXF E6 TS809RCXF EL TS810RCXF EP TS809/810/809R/810R 5-6 2004/09 rev. D SOT-23 Mechanical Drawing A B F A B C D E SOT-23 DIMENSION MILLIMETERS INCHES MIN MAX MIN MAX 2.88 2.91 0.113 0.115 0.39 0.42 0.015 0.017 1.78 2.03 0.070 0.080 0.51 0.61 0.020 0.024 1.59 1.66 0.063 0.065 F G 1.04 0.07 DIM E G D 1.08 0.09 0.041 0.003 C TS809/810/809R/810R 6-6 2004/09 rev. D 0.043 0.004