TC651AAVUA

TC650/TC651 Tiny Integrated Temperature Sensor & Brushless DC Fan Controller with Over-Temperature Alert Features • Integrated Temperature Sensing and Multi-speed Fan Control • Built-in Over Temperature Alert (TOVER) • Temperature Proportional Fan Speed Control for Acoustic Noise Reduction and Longer Fan Life • Pulse Width Modulation Output Drive for Cost and Power Savings • Solid-State Temperature Sensing • ±1°C (Typical) Accuracy from 25°C to +70°C • 2.8V – 5.5V Operating Range • TC651 includes Auto Fan Shutdown • Low Operating Current: 50µA (Typical) Package Type 8-Pin MSOP 8-Pin SOIC VDD 1 NC 2 SHDN 3 GND 4 8 PWM TC650 TC651 7 GND 6 TOVER 5 NC General Description The TC650/TC651 are integrated temperature sensors and brushless DC fan speed controllers. The TC650/ TC651 measure their junction temperature and control the speed of the fan based on that temperature, making them especially suited for applications in modern electronic equipment. Temperature data is converted from the on-chip thermal sensing element and translated into a fractional fan speed from 40% to 100%. A temperature selection guide in the data sheet is used to choose the low and high temperature limits to control the fan. The TC650/TC651 also include a single trip point over temperature alert (TOVER) that eliminates the need for additional temperature sensors. In addition, the TC651 features an auto fan shutdown function for additional power savings. The TC650/TC651 are easy to use, require no software overhead and are therefore the ideal choice for implementing thermal management in a variety of systems. Applications • • • • • • Thermal Protection For Personal Computers Digital Set-Top Boxes Notebook Computers Data Communications Power Supplies Projectors Related Literature • Application Note: AN771 Device Selection Table Part Number TC650XXVUA TC651XXVUA Package 8-Pin SOIC 8-PinMSOP Temperature Range -40°C to +125 °C -40°C to +125 °C X A B C D E F G Temperature 25 30 35 40 45 50 55 The "X" denotes a suffix for temperature threshold settings. Contact factory for other temperature ranges. 2002 Microchip Technology Inc. DS21450B-page 1 © TC650/TC651 Typical Application Diagram +12V +5V VDD TC650 TC651 1 VDD 2 NC PWM 8 GND 7 CSLOW DC Fan 500mA 3 SHDN TOVER 6 4 GND NC 5 GND GND SHDN Control Over-Temp. Alert µController © DS21450B-page 2 2002 Microchip Technology Inc. TC650/TC651 1.0 ELECTRICAL CHARACTERISTICS *Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings* Input Voltage (VDD to GND) ................................... +6V Output Voltage (OUT to GND) ................................. 6V Voltage On Any Pin ....... (GND – 0.3V) to (VDD + 0.3V) Package Thermal Resistance (θJA ) .............. 250°C/W Operating Temperature Range .......... -40°C to +125°C Storage Temperature ......................... -65°C to +150°C TC650/TC651 ELECTRICAL SPECIFICATIONS Electrical Characteristics: VDD = 2.8V to 5.5V, SHDN = VDD, TA = -40°C to 125°C unless otherwise specified. Symbol VDD IDD SHDN Input VIH VIL PWM Output VOL VOH tR tF fOUT tSTARTUP PWM Output Low Voltage PWM Output High Voltage PWM Rise Time PWM Fall Time PWM Frequency Start-up Time — VDD - 0.5 — — 10 — — — 10 10 15 32/fOUT 0.3 — — — — — V V µsec µsec Hz sec VDD Rises from GND, or SHDN Released ISINK = 1mA ISOURCE = 5mA IOH = 5mA, 1nF from PWM to GND IOL = 1mA, 1nF from PWM to GND SHDN Input High Threshold SHDN Input Low Threshold 65 — — — — 15 %VDD %VDD Parameter Supply Voltage Supply Current Min 2.8 — Typ. — 50 Max 5.5 90 Units V µA PWM, TOVER are open Test Conditions Temperature Accuracy TH ACC (TH –TL) ACC THYST TOVER Output VHIGH VLOW TOVER ACC TOVER HYST TOVER Output High Voltage TOVER Output Low Voltage Absolute Accuracy Trip Point Hysteresis VDD - 0.5 — — — — — TH + 10 5 — 0.4 — — V V °C °C ISOURCE = 1.2mA ISINK = 2.5mA At Trip Point High Temperature Accuracy Temp. Range Accuracy Auto-shutdown Hysteresis TH – 3 -1.0 -2.5 — TH — — (TH -TL)/5 TH + 3 +1.0 +2.5 — °C °C °C °C Note 1 (TH - TL) ≤ 20°C (TH - TL) ≥ 20°C TC651 Only Note 1: Transition from 90% to 100% Duty Cycle. 2002 Microchip Technology Inc. DS21450B-page 3 © TC650/TC651 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: Pin No. (8-Pin MSOP) (8-Pin SOIC) 1 2 3 4 5 6 7 8 PIN FUNCTION TABLE Symbol VDD NC SHDN GND NC TOVER GND PWM Description Power Supply Input. May be independent of fan power supply. No Internal Connect. Fan Shutdown, Active-Low Input. During Shutdown mode the chip still monitors temperature and TOVER is low if temperature rises above factory set point. Ground. Ground return for all TC650/TC651 functions. No Connect. Over-Temperature Alert, Active-Low Output. Ground. PWM Fan Drive Output. Pulse width modulated rail-to-rail logic output. Nominal Frequency is 15Hz. © DS21450B-page 4 2002 Microchip Technology Inc. TC650/TC651 3.0 DETAILED DESCRIPTION FIGURE 3-1: VDD Temperature Set Point and Trim Range A/D Converter Oscillator Temperature Sensor The TC650/TC651 acquire and convert their junction temperature (TJ) information from an on-chip solid-state sensor with a typical accuracy of ±1°C. The temperature data is digitally stored in an internal register. The register is compared with pre-defined threshold values. The six threshold values are equally distributed over a pre-defined range of temperatures (see Table 3-1 and Table 3-2). The TC650/TC651 control the speed of a DC brushless fan using a fractional speed control scheme. The output stage requires only a 2N2222-type small-signal BJT for fans up to 300mA. For larger current fans (up to 1 Amp) a logic-level N-channel MOSFET may be used. In addition to controlling the speed of the fan, the TC650/TC651 include an on-chip over-temperature alarm (TOVER) that gives a low signal when the temperature of the chip exceeds TH by 10°C, (typical). This feature eliminates the need for a separate temperature sensor for over-temperature monitoring. FUNCTIONAL BLOCK DIAGRAM TOVER V+ SHDN Duty Cycle Logic Control PWM 3.1 PWM Output TABLE 3-1: TEMPERATURE RANGE DEFINITION FOR TC650 (MINIMUM-SPEED MODE) PWM Duty Cycle 40% 50% 60% 70% 80% 90% 100% 100% with Over Temp Alert (TOVER = L) Temperature (T = TJ) T < TL TL< = T < T1 T1 < = T < T2 T2 < = T