STM6600AS24DM6F

STM6600 STM6601 Smart push-button on/off controller with Smart ResetTM and power-on lockout Features ■ ■ ■ ■ Operating voltage 1.6 V to 5.5 V Low standby current of 1 µA Adjustable Smart Reset™ assertion delay time driven by external CSRD Power-up duration determined primarily by push-button press (STM6600) or by fixed time period, tON_BLANK (STM6601) Debounced PB and SR inputs PB and SR ESD inputs withstand voltage up to ±15 kV (air discharge) ±8 kV (contact discharge) Active high or active low enable output option (EN or EN) provides control of MOSFET, DC-DC converter, regulator, etc. Secure startup, interrupt, Smart Reset™ or power down driven by push-button Precise 1.5 V voltage reference with 1% accuracy Industrial operating temperature –40 to +85 °C Available in TDFN12 2 x 3 mm package TDFN12 ■ ■ ■ ■ ■ ■ ■ Applications ■ ■ ■ ■ ■ Portable devices Terminals Audio and video players Cell phones and smart phones PDAs, palmtops, organizers Table 1. Device STM6600 STM6601 Device summary RST open drain(1) open drain(1) CSRD ✓ ✓ PB / SR ✓ ✓ EN or EN push-pull push-pull INT open drain(1) open drain(1) Startup process PB must be held low until the PSHOLD(2) confirmation PB can be released before the PSHOLD(2) confirmation 1. External pull-up resistor needs to be connected to open drain outputs. 2. For a successful startup, the PSHOLD (Power Supply Hold) needs to be pulled high within specific time, tON_BLANK. June 2010 Doc ID 15453 Rev 7 1/51 www.st.com 1 Contents STM6600 - STM6601 Contents 1 2 3 4 5 6 7 8 9 10 11 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Product selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 2/51 Doc ID 15453 Rev 7 STM6600 - STM6601 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 TDFN12 (2 x 3 mm) package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Carrier tape dimensions for TDFN12 (2 mm x 3 mm) package . . . . . . . . . . . . . . . . . . . . . 45 STM6600 ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 STM6601 ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 STM6600 product selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 STM6601 product selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Doc ID 15453 Rev 7 3/51 List of figures STM6600 - STM6601 List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41. Figure 42. Figure 43. Application hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Basic functionality (option with enable deassertion after long push) . . . . . . . . . . . . . . . . . . 6 Basic functionality (option with RST assertion after long push) . . . . . . . . . . . . . . . . . . . . . . 6 Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 TDFN12 pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Successful power-up on STM6600 (PB released prior to tON_BLANK expiration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Successful power-up on STM6600 (tON_BLANK expires prior to PB release) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Unsuccessful power-up on STM6600 (PB released prior to tON_BLANK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Unsuccessful power-up on STM6600 (tON_BLANK expires prior to PB release) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Successful power-up on STM6601 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Unsuccessful power-up on STM6601 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Power-up on STM660x with voltage dropout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 PB interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Long push, PB pressed first . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Long push, SR pressed first . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Invalid long push . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Long push (option with RST assertion). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Long push (option with enable deassertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Undervoltage detected for tSRD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 PBOUT output waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Supply current vs. temperature, normal state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Supply current vs. temperature, standby state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Supply current vs. supply voltage, normal state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Supply current vs. supply voltage, standby state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Threshold vs. temperature, VTH+ = 3.4 V (typ.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Threshold hysteresis vs. temperature, VHYST = 200 mV (typ.) . . . . . . . . . . . . . . . . . . . . . . 30 Debounce period vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 CSRD charging current vs. temperature, VCC = 3.6 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Output low voltage vs. output low current, TA = 25°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Output high voltage vs. output high current, TA = 25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Output voltage vs. supply voltage, IOUT = 1 mA, TA = 25 °C . . . . . . . . . . . . . . . . . . . . . . . 33 Input voltage vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Reference output voltage vs. temperature, VCC = 2.0 V. . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Reference output voltage vs. load current, VCC = 2.0 V, TA = 25 °C . . . . . . . . . . . . . . . . . 34 Reference output voltage vs. supply voltage, TA = 25 °C . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Reference startup, IREF = 15 µF, TA = 25 °C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Reference response to steps on supply voltage, IREF = 15 µA, TA = 25 °C . . . . . . . . . . . . 36 Reference response to steps in load current, VCC = 3.6 V, TA = 25 °C . . . . . . . . . . . . . . . 37 TDFN12 (2 x 3 mm) package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 TDFN12 (2 x 3 mm) recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Carrier tape for TDFN12 (2 mm x 3 mm) package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Description 1 Description The STM6600-01 devices monitor the state of connected push-button(s) as well as sufficient supply voltage. An enable output controls power for the application through the MOSFET transistor, DC-DC converter, regulator, etc. If the supply voltage is above a precise voltage threshold, the enable output can be asserted by a simple press of the button. Factoryselectable supply voltage thresholds are determined by highly accurate and temperaturecompensated references. An interrupt is asserted by pressing the push-button during normal operation and can be used to request a system power-down. The interrupt is also asserted if undervoltage is detected. By a long push of one button (PB) or two buttons (PB and SR) either a reset is asserted or power for the application is disabled depending on the option used. The device also offers additional features such as precise 1.5 V voltage reference with very tight accuracy of 1%, separate output indicating undervoltage detection and separate output for distinguishing between interrupt by push-button or undervoltage. The device consumes very low current of 6 µA during normal operation and only 1 µA current during standby. The STM6600-01 is available in the TDFN12 package and is offered in several options among features such as selectable threshold, hysteresis, timeouts, output types, etc. (see Table 8 and Table 9 for more information). Figure 1. Application hookup 1. A resistor is required for open drain output type only. A 10 kΩ pull-up is sufficient in most applications. 2. Capacitor CREF is mandatory on VREF output (even if VREF is not used). Capacitor value of 1 µF is recommended. 3. For the STM6601 the processor has to confirm the proper power-on during the fixed time period, tON_BLANK. This failsafe feature prevents the user from turning on the system when there is a faulty power switch or an unresponsive microprocessor. Doc ID 15453 Rev 7 5/51 Description Figure 2. STM6600 - STM6601 Basic functionality (option with enable deassertion after long push) POWER-UP(1) PB INTERRUPT (short push) POWER DOWN (long push) SR EN INT interrupt interrupt AM00243v1 1. For power-up the battery voltage has to be above VTH+ threshold. Figure 3. Basic functionality (option with RST assertion after long push) POWER-UP(1) PB INTERRUPT (short push) POWER DOWN (long push) SR RST INT interrupt interrupt AM00243bv1 1. For power-up the battery voltage has to be above VTH+ threshold. Figure 4. Logic diagram VCC EN (EN) PB SR PSHOLD CSRD RST STM6600 STM6601 INT PBOUT VCC LO VREF GND AM00236v1 6/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Table 2. Pin number 1 2 3 4 5 6 7 8 9 10 11 12 Description Pin descriptions Symbol VCC SR VREF PSHOLD CSRD PB VCCLO PBOUT EN or EN RST INT GND Power supply input Smart Reset™ button input Precise 1.5 V voltage reference PSHOLD input Adjustable Smart Reset™ delay time input Push-button input Output for high threshold comparator output (VTH+) Status of PB push-button input Enable output Reset output Interrupt output Ground Function Figure 5. TDFN12 pin connections VCC SR VREF PSHOLD 1 2 3 4 12 11 10 9 8 7 GND INT RST EN (EN) PBOUT VCC LO AM00245v1 CSRD 5 PB 6 Doc ID 15453 Rev 7 7/51 Description Figure 6. Block diagram STM6600 - STM6601 VCC LO + VCC VCC RPB (1) VCC + – VTH– EN (EN) – (2) tREC generator RST RSR VTH+ PSHOLD PB Glitch immunity Edge detector debounce Glitch immunity Edge detector debounce Smart logic RPSHOLD (3) INT SR VREF SRD logic 1.5 V GND PBOUT CSRD AM00237v3 1. Internal pull-up resistor connected to PB input (see Table 5 for precise specifications). 2. Optional internal pull-up resistor connected to SR input (see Table 5 for precise specifications and Table 10 for detailed device options). 3. Internal pull-down resistor is connected to PSHOLD input only during startup (see Figure 7, 8, 9, 10, 11, 12, 13, and 18). 8/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Pin descriptions 2 Pin descriptions VCC - power supply input VCC is monitored during startup and normal operation for sufficient voltage level. Decouple the VCC pin from ground by placing a 0.1 µF capacitor as close to the device as possible. SR - Smart Reset™ button input This input is equipped with voltage detector with a factory-trimmed threshold and has ±8 kV HBM ESD protection. Both PB and SR buttons have to be pressed and held for tSRD period so the long push is recognized and the reset is asserted (or the enable output is deasserted depending on the option) - see Figure 15, 16, and 17. Active low SR input is usually connected to GND through the momentary push-button (see Figure 1) and it has an optional 100 kΩ pull-up resistor. It is also possible to drive this input using an external device with either open drain (recommended) or push-pull output. Open drain output can be connected in parallel with push-button or other open drain outputs, which is not possible with push-pull output. VREF - external precise 1.5 V voltage reference This 1.5 V voltage reference is specified with very tight accuracy of 1% (see Table 5). It has proper output voltage as soon as the reset output is deasserted (i.e. after tREC expires) and it is disabled when the device enters standby mode. A mandatory capacitor needs to be connected to VREF output (even if VREF is not used). Capacitor value of 1 µF is recommended. PSHOLD input This input is equipped with a voltage detector with a factory-trimmed threshold. It is used to confirm correct power-up of the device (if EN or EN is not asserted) or to initiate a shutdown (if EN or EN is asserted). Forcing PSHOLD high during power-up confirms the proper start of the application and keeps enable output asserted. Because most processors have outputs in high-Z state before initialization, an internal pull-down resistor is connected to PSHOLD input during startup (see Figure 7, 8, 9, 10, 11, 12, 13, and 18). Forcing the PSHOLD signal low during normal operation deasserts the enable output (see Figure 14). Input voltage on this pin is compared to an accurate voltage reference. CSRD - Smart Reset™delay time input A capacitor to ground determines the additional time (tSRD) that PB with SR must be pressed and held before a long push is recognized. The connected CSRD capacitor is charged with ISRD current. Additional Smart Reset™ delay time tSRD ends when voltage on the CSRD capacitor reaches the VSRD voltage threshold. It is recommended to use a low ESR capacitor (e.g. ceramic). If the capacitor is not used, leave the CSRD pin open. If no capacitor is connected, there is no tSRD and a long push is recognized right after tINT_Min expires (see Figure 18 and 19). Doc ID 15453 Rev 7 9/51 Pin descriptions PB - power ON switch STM6600 - STM6601 This input is equipped with a voltage detector with a factory-trimmed threshold and has ± 8 kV HBM ESD protection. When the PB button is pressed and held, the battery voltage is detected and EN (or EN) is asserted if the battery voltage is above the threshold VTH+ during the whole tDEBOUNCE period (see Figure 13). A short push of the push-button during normal operation can initiate an interrupt through debounced INT output (see Figure 14) and a long push of PB and SR simultaneously can either assert reset output RST (see Figure 18) or deassert the EN or EN output (see Figure 19) based on the option used. Note: A switch to GND must be connected to this input (e.g. mechanical push-button, open drain output of external circuitry, etc.), see Figure 1. This ensures a proper startup signal on PB (i.e. a transition from full VCC below specified VIL). PB input has an internal 100 kΩ pull-up resistor connected. VCCLO - high threshold detection output During power-up, VCCLO is low when VCC supply voltage is below the VTH+ threshold. After successful power-up (i.e. during normal operation) VCCLO is low anytime undervoltage is detected (see Figure 13). Output type is active low and open drain by default. Open drain output type requires a pullup resistor. A 10 kΩ is sufficient in most applications. VCCLO is floating when STM660x is in standby mode. PBOUT - PB input state If the push-button PB is pressed, the pin stays low during the tDEBOUNCE time period. If PB is asserted for the entire tDEBOUNCE period, PBOUT will then stay low for at least tINT_Min. If PB is asserted after tINT_Min expires, PBOUT w ill return high as soon as PB is deasserted (see Figure 22). PBOUT ignores PB assertion during an undervoltage condition. At startup on the STM6601 PBOUT will respond only to the first PB assertion and any other assertion will be ignored until tON_BLANK expires. This output is active low and open drain by default. Open drain output type requires a pull-up resistor. A 10 kΩ is sufficient in most applications. 10/51 Doc ID 15453 Rev 7 STM6600 - STM6601 EN or EN - enable output Pin descriptions This output is intended to enable system power (see Figure 1). EN is asserted high after a valid turn-on event has been detected and confirmed (i.e. push-button has been pressed and held for tDEBOUNCE or more and VCC > VTH+ voltage level has been detected - see Figure 13). EN is released low if any of the conditions below occur: a) the push-button is released before PSHOLD is driven high (valid for STM6600, see Figure 9) or tON_BLANK expires before PSHOLD is driven high during startup (valid for both STM6600 and STM6601, see Figure 10 and 12). PSHOLD is driven low during normal operation (see Figure 14). an undervoltage condition is detected for more than tSRD + tINT_Min + tDEBOUNCE (see Figure 21). a long push of the buttons is detected (only for the device with option “EN deasserted by long push” - see Figure 19) or PSHOLD is not driven high during tON_BLANK after a long push of the buttons (only for the device with option “RST asserted by long push” - see Figure 18). b) c) d) Described logic levels are inverted in case of EN output. Output type is push-pull by default. RST - reset output This output pulls low for tREC: a) during startup. PB has been pressed (falling edge on the PB detected) and held for at least tDEBOUNCE and VCC > VTH+ (see Figure 7, 8, 9, 10, 11, 12 and 13 for more details). after long push detection (valid only for the device with option “RST asserted by long push”). PB has been pressed (falling edge on the PB detected) and held for more than tDEBOUNCE + tSRD (additional Smart Reset™ delay time can be adjusted by the external capacitor CSRD) - see Figure 18. b) Output type is active low and open drain by default. Open drain output type requires a pullup resistor. A 10 kΩ is sufficient in most applications. INT - interrupt output While the system is under normal operation (PSHOLD is driven high, power for application is asserted), the INT is driven low if: a) b) VCC falls below VTH- threshold (i.e. undervoltage is detected - see Figure 20 and 21). the falling edge on the PB is detected and the push-button is held for tDEBOUNCE or more. INT is driven low after tDEBOUNCE and stays low as long as PB is held. The INT signal is held high during power-up. The state of the PBOUT output can be used to determine if the interrupt was caused by either the assertion of the PB input, or was due to the detection of an undervoltage condition on VCC. INT output is asserted low for at least tINT_Min. Output type is active low and open drain by default. Open drain output type requires a pullup resistor. A 10 kΩ is sufficient in most applications. GND - ground Doc ID 15453 Rev 7 11/51 Operation STM6600 - STM6601 3 Operation The STM6600-STM6601 simplified smart push-button on/off controller with Smart Reset™ and power-on lockout enables and disables power for the application depending on pushbutton states, signals from the processor, and battery voltage. Power-on Because most of the processors have outputs in high-Z state before initialization, an internal pull-down resistor is connected to PSHOLD input during startup (see Figure 7, 8, 9, 10, 11, 12, 13, and 18). To power up the device the push-button PB has to be pressed for at least tDEBOUNCE and VCC has to be above VTH+ for the whole tDEBOUNCE period. If the battery voltage drops below VTH+ during the tDEBOUNCE, the counter is reset and starts to count again when VCC > VTH+ (see Figure 13). After tDEBOUNCE the enable signal is asserted (EN goes high, EN goes low), reset output RST is asserted for tREC and then the startup routine is performed by the processor. During initialization, the processor sets the PSHOLD signal high. On the STM6600 the PSHOLD signal has to be set high prior to push-button release and tON_BLANK expiration, otherwise the enable signal is deasserted (EN goes low, EN goes high) - see Figure 7, 8, 9, and 10. The time up to push-button release represents the maximum time allowed for the system to power up and initialize the circuits driving the PSHOLD input. If the PSHOLD signal is low at push-button release, the enable output is deasserted immediately, thus turning off the system power. If tON_BLANK expires prior to push-button release, the PSHOLD state is checked at its expiration. This safety feature disables the power and prevents discharging the battery if the push-button is stuck or it is held for an unreasonable period of time and the application is not responding (see Figure 8 and 10). PB status, INT status and VCC undervoltage detection are not monitored until power-up is completed. On the STM6601 the PSHOLD signal has to be set high before tON_BLANK expires, otherwise the enable signal is deasserted - see Figure 11 and 12. In this case the tON_BLANK period is the maximum time allowed for the power switch and processor to perform the proper poweron. If the PSHOLD signal is low at the end of the blanking period, the enable output is released immediately, thus turning off the system power. PB status, INT status and VCC undervoltage detection are not monitored during the entire tON_BLANK period. This failsafe feature prevents the user from turning on the system when there is a faulty power switch or an unresponsive microprocessor. Push-button interrupt If the device works under normal operation (i.e. PSHOLD is high) and the push-button PB is pressed for more than tDEBOUNCE, a negative pulse with minimum tINT_Min width is generated on the INT output. By connecting INT to the processor interrupt input (INT or NMI) a safeguard routine can be performed and the power can be shut down by setting PSHOLD low - see Figure 14. Forced power-down mode The PSHOLD output can be forced low anytime during normal operation by the processor and can deassert the enable signal - see Figure 14. 12/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Undervoltage detection Operation If VCC voltage drops below VTH- voltage threshold during normal operation, the INT output is driven low (see Figure 20 and Figure 21). If an undervoltage condition is detected for tDEBOUNCE + tINT_Min + tSRD, the enable output is deasserted (see Figure 21). Hardware reset or power-down while system not responding If the system is not responding and the system hangs, the PB and SR push-buttons can be pressed simultaneously longer than tDEBOUNCE + tINT_Min + tSRD, and then a) b) either the reset output RST is asserted for tREC and the processor is reset (valid only for the device with option “RST asserted by long push”) – see Figure 18 or the power is disabled by EN or EN signal (valid only for the device with option “EN deasserted by long push”) – see Figure 19 The tSRD is set by the external capacitor connected to the CSRD pin. Standby If the enable output is deasserted (i.e. EN is low or EN is high), the STM660x device enters standby mode with low current consumption (see Table 5). In standby mode PB input is only monitored for the falling edge. The external 1.5 V voltage reference is also disabled in standby mode. Doc ID 15453 Rev 7 13/51 W aveforms STM6600 - STM6601 4 Figure 7. Waveforms Successful power-up on STM6600 (PB released prior to tON_BLANK expiration) Push-button pressed and PB connected to GND processor sets PSHOLD PB released prior to t ON_BLANK expiration PSHOLD state detected as high EN remains asserted PB(1) PSHOLD(2) VCC undervoltage detection ignored PSHOLD ignored internal pull-down resistor connected to PSHOLD input EN(3) RST tDEBOUNCE tREC tON_BLANK Note: INT signal is held high during power-up (i.e. until PB release in this case). VCC is considered VCC > VTH+. AM00247v3 1. PB detection on falling and rising edges. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. EN signal is high even after PB release, because processor sets PSHOLD signal high before PB is released. 14/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Figure 8. Successful power-up on STM6600 (tON_BLANK expires prior to PB release) Waveforms Push-button pressed and PB connected to GND processor sets PSHOLD tON_BLANK expired prior to PB release PSHOLD state detected as high EN remains asserted PB released PB(1) PSHOLD(2) VCC undervoltage detection ignored PSHOLD ignored internal pull-down resistor connected to PSHOLD input EN(3) RST tDEBOUNCE tREC tON_BLANK Note: INT signal is held high during power-up (i.e. until tON_BLANK expires in this case). VCC is considered VCC > VTH+. AM00247bv2 1. PB detection on falling and rising edges. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. tON_BLANK expires prior to PB release so PSHOLD is checked at its expiration. Doc ID 15453 Rev 7 15/51 W aveforms STM6600 - STM6601 Figure 9. Unsuccessful power-up on STM6600 (PB released prior to tON_BLANK) Push-button pressed and PB connected to GND PB released PSHOLD state detected as low EN deasserted PB(1) PSHOLD(2) VCC undervoltage detection ignored PSHOLD ignored internal pull-down resistor connected to PSHOLD input PB status ignored EN(3) RST tDEBOUNCE tREC tON_BLANK tEN_OFF Note: INT signal is held high during power-up (i.e. until PB release in this case). VCC is considered VCC > VTH+. AM00248v3 1. PB detection on falling and rising edges. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. EN signal goes low with PB release, because processor did not force PSHOLD signal high. 16/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Waveforms Figure 10. Unsuccessful power-up on STM6600 (tON_BLANK expires prior to PB release) tON_BLANK expired prior to PB release PSHOLD state detected as low EN is deasserted Push-button pressed and PB connected to GND PB released PB (1) VCC undervoltage detection ignored PSHOLD ignored internal pull-down resistor connected to PSHOLD input PB status ignored PSHOLD(2) EN(3) RST tDEBOUNCE tREC tON_BLANK tEN_OFF Note: INT signal is held high during power-up (i.e. until tON_BLANK expires in this case). VCC is considered VCC > VTH+. AM00248bv2 1. PB detection on falling and rising edges. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. tON_BLANK expires prior to PB release so PSHOLD is checked at its expiration. Doc ID 15453 Rev 7 17/51 W aveforms STM6600 - STM6601 Figure 11. Successful power-up on STM6601 tON_BLANK expires processor PSHOLD state detected as high sets PSHOLD EN remains asserted Push-button pressed and PB connected to GND (1) PB PB status and V CC undervoltage detection ignored PSHOLD ignored (2) PSHOLD internal pull-down resistor connected to PSHOLD input EN (3) RST t DEBOUNCE t REC t ON_BLANK Note: INT signal is held high during power-up (i.e. until tON_BLANK expires in the case of the STM6601). VCC is considered VCC > VTH+. 1. PB detection on falling edge. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. PSHOLD signal is ignored during tON_BLANK. When tON_BLANK expires, the level of the PSHOLD signal is high therefore the EN signal remains asserted. AM00250v2 18/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Waveforms Figure 12. Unsuccessful power-up on STM6601 Push-button pressed and PB connected to GND tON_BLANK expires PSHOLD state detected as low Push-button pressed and PB connected to GND EN deasserted (1) PB PSHOLD ignored intenal pull-down resistor connected to PSHOLD input PSHOLD (2) (3) EN RST t DEBOUNCE t REC Note: INT signal is held high during power-up (i.e. until tON_BLANK expires in the case of the STM6601). VCC is considered VCC > VTH+. AM00238v2 1. PB detection on falling edge. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. PSHOLD signal is ignored during tON_BLANK. When tON_BLANK expires, the level of the PSHOLD signal is not high therefore the EN signal goes low. Even releasing the PB button after the tON_BLANK will not prevent this. Doc ID 15453 Rev 7 19/51 W aveforms STM6600 - STM6601 Figure 13. Power-up on STM660x with voltage dropout Push-button pressed and PB connected to GND VTH+ VTH– VCC VCC undervoltage detected VCC–Min VCC goes above VTH+ and tDEBOUNCE is counted again VCC LO VCC drop (1) PB (2) PSHOLD internal pull-down resistor connected to PSHOLD input INT (3) INT signal is held high during power-up EN RST < t DEBOUNCE t DEBOUNCE tREC < t ON_BLANK AM00249v2 1. PB detection on falling and rising edges. 2. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during power-up. 3. INT signal is held high during power-up. 20/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Figure 14. PB interrupt Waveforms processor interrupt starts power-down sequence Push-button pressed and PB connected to GND processor sets PSHOLD low and EN is deasserted accordingly PB status ignored PB (1,2) PSHOLD PB status ignored VCC undervoltage detection ignored t DEBOUNCE t INT_Min tEN_OFF Note: VCC is considered VCC > VTH+. 1. PB detection on falling edge. 2. PB is released within tSRD and that is why NO reset is asserted and EN is NOT deasserted immediately. AM00251v2 Doc ID 15453 Rev 7 21/51 W aveforms Figure 15. Long push, PB pressed first Push-button PB is pressed Push-button tSRD starts to SR is pressed be counted STM6600 - STM6601 PB tDEBOUNCE tSRD set by CSRD SR tDEBOUNCE INT PB status ignored tINT_Min AM00257v1 Figure 16. Long push, SR pressed first Push-button SR is pressed Push-button PB is pressed tSRD starts to be counted PB tDEBOUNCE SR tSRD set by CSRD INT PB status ignored tINT_Min AM00258v1 22/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Figure 17. Invalid long push Push-button PB is pressed Push-button SR is pressed tSRD starts to be counted Waveforms Any rising edge will stop tSRD to count regardless of glitch immunity PB tDEBOUNCE SR < tSRD set by CSRD INT PB status ignored tINT_Min AM00259v1 Doc ID 15453 Rev 7 23/51 W aveforms Figure 18. Long push (option with RST assertion) Push-button pressed and PB connected to GND Push-button held even after tSRD expires therefore RST is asserted STM6600 - STM6601 tON_BLANK expires PSHOLD state detected as high therefore EN remains high After tON_BLANK PB is monitored for falling edge PB tSRD(1) set by CSRD tON_BLANK (valid for STM6600 and STM6601) SR INT (2) PB status ignored INT can go high, if PB goes high, but system freezes and processor won’t respond RST VCC undervoltage detection status ignored PSHOLD ignored PSHOLD (3, 4) if system freezes, processor won’t respond to any INT status change internal pull-down resistor connected to PSHOLD input tDEBOUNCE t INT_Min tREC tDEBOUNCE Note: EN is high. 1. tSRD period is set by external capacitor CSRD. 2. PB ignored during tINT_Min. AM00252v2 3. PSHOLD signal is ignored during tON_BLANK. Its level is checked after tON_BLANK expires and if it is high the EN signal remains asserted, otherwise EN goes low. 4. Internal pull-down resistor 300 kΩ is connected to PSHOLD input during startup when device is reset. 24/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Figure 19. Long push (option with enable deassertion) Push-button pressed and PB connected to GND Push-button held even after tSRD expires and EN is deasserted After tEN_OFF expires PB is monitored for falling edge Waveforms PB tSRD(1) set by CSRD PB status ignored SR INT (2) INT can go high, if PB goes high, PB status but system freezes and processor ignored won’t respond EN(3) VCC undervoltage detection status ignored PSHOLD tDEBOUNCE if system freezes, processor won’t respond to any INT status change t INT_Min tEN_OFF tDEBOUNCE AM00253v2 1. tSRD period is set by external capacitor CSRD. 2. PB ignored during tINT_Min. 3. After tSRD expires EN is forced low. Doc ID 15453 Rev 7 25/51 W aveforms Figure 20. Undervoltage detected for tSRD VCC undervoltage detected VTH+ VCC is below VTH+ even after tSRD expires thus power is disabled (EN goes low) and PB is monitored for regular startup VCC (1) VCC-Min VTH– tSRD(2) set by CSRD VCCLO PSHOLD VCC undervoltage detection ignored PB status ignored INT EN tDEBOUNCE tINT_Min PB status ignored tEN_OFF AM00255v1 1. After tSRD expires VCC is still insufficient (below VTH+) thus power is disabled (EN goes low or EN goes high). 2. tSRD period is set by external capacitor CSRD. 26/51 Doc ID 15453 Rev 7 STM6600 - STM6601 Waveforms Figure 22. PBOUT output waveform