MAX807LCPE Microprocessor Supervisory Circuit With Precision 4.675V Voltage Monitoring 20mA/250mA DIP-16
The MAX807LCPE from Maxim Integrated Products is a full-featured microprocessor (µP) supervisory circuit built with BiCMOS technology for improved ±1.5% reset-threshold precision. It is the MAX807L version, featuring a precision 4.675V reset threshold, housed in a 16-pin Plastic DIP (PDIP) package and specified for operation from 0°C to +70°C from a nominal +5V supply.
The MAX807 reduces the complexity and number of components needed to monitor power-supply and battery-control functions in µP systems. A 70µA supply current makes it ideal for use in portable equipment, while a 2ns chip-enable propagation delay and 250mA output current capability (20mA in battery-backup mode) make it suitable for larger, higher-performance equipment.
Features
- Precision 4.675V voltage monitoring (MAX807L version), ±1.5% reset accuracy
- 200ms power-OK/reset time delay
- RESET and RESET outputs (active-low and active-high)
- RESET output guaranteed valid down to VCC = 1V
- Manual-reset input (active-low, internal pullup, no debounce needed)
- Independent watchdog timer (1.6s typ timeout)
- 1µA standby current in battery-backup mode; 70µA (typ) operating supply current
- Power switching: 250mA in VCC mode, 20mA in battery-backup mode
- Two-stage power-fail warning: low-line threshold 52mV above reset threshold, ±1.5% accuracy
- On-board gating of chip-enable signals with 2ns CE propagation delay (write-protects CMOS RAM/EEPROM)
- Backup-battery switchover and backup-battery monitor (BATT OK flag)
- 2.275V threshold detector for power-fail warning / low-battery detection / monitoring supplies other than +5V
- 16-pin Plastic DIP package, 0°C to +70°C
Specifications
| Parameter | Specification |
|---|---|
| PRODUCT IDENTIFICATION | |
| Part Number | MAX807LCPE |
| Manufacturer | Maxim Integrated Products |
| IC Type | Full-Featured Microprocessor (µP) Supervisory Circuit with ±1.5% Reset Accuracy |
| Reset Threshold Version | L – 4.675V (typical) |
| Package | 16-Pin Plastic DIP (PDIP) |
| Operating Temperature Range | 0°C to +70°C |
| Nominal Supply Voltage (VCC) | +5V (operating range 4.60V to 5.5V for the MAX807L) |
| Datasheet Reference | Maxim 19-0433; Rev 4; 11/05 |
| RESET & LOW-LINE SUPERVISION | |
| Reset Threshold Voltage (VRST), MAX807L | 4.675V typ (4.600V min, 4.750V max); VCC rising and falling |
| Reset Threshold Accuracy | ±1.5% |
| Reset Threshold Hysteresis | 13mV typ |
| LOW LINE to Reset Threshold (VLR) | 52mV typ (30mV min, 70mV max); VCC falling |
| LOW LINE Threshold (VCC rising), MAX807L | 4.73V min to 4.81V max |
| Low-Line Threshold Accuracy | ±1.5%, 52mV above reset threshold |
| Reset Active-Timeout Period (tRP) | 200ms typ (140ms min, 280ms max); VCC rising |
| VCC to RESET Delay | 26µs typ (VCC falling at 1mV/µs) |
| VCC to LOW LINE Delay | 24µs typ (VCC falling at 1mV/µs) |
| RESET Validity | Guaranteed correct (logic low) for VCC down to 1V; maintained for 0V < VCC < VRST with VBATT > 2V |
| WATCHDOG TIMER | |
| Watchdog-Timeout Period (tWD) | 1.6s typ (1.12s min, 2.24s max) |
| Minimum Watchdog Input Pulse Width | 100ns typ |
| WDI Threshold Voltage | VIL = 0.8V max; VIH = 0.75 × VCC min |
| WDI Input Current (reset deasserted) | -10µA typ / -50µA max (WDI = 0V); 16µA typ / 50µA max (WDI = VCC) |
| Watchdog-Fault Output (WDO) | Low if WDI not toggled within tWD; high during reset or when WDI is unconnected; connect WDO to MR to force a reset on each watchdog fault |
| POWER SUPPLY & BATTERY BACKUP | |
| Operating Voltage Range (VBATT, VCC) | 0V to 5.5V (either input can go to 0V if the other is greater than 2.0V) |
| Supply Current, Normal Operating Mode (excl. IOUT) | 70µA typ, 110µA max |
| Supply Current, Battery-Backup Mode (excl. IOUT) | 0.4µA typ, 1µA max (VCC = 0V, VBATT = 2.8V) |
| BATT Standby Current (normal mode) | ±0.1µA typ, ±1.0µA max (VBATT = 2.8V, VCC = 3.0V) |
| Output Current Capability | 250mA in VCC mode; 20mA in battery-backup mode |
| VCC-to-OUT On-Resistance | 1.0 to 1.2Ω typ (1.4 to 2.5Ω max, depending on VCC / IOUT) |
| BATT-to-OUT On-Resistance | 16Ω typ (VBATT = 2.0V, IOUT = 5mA); 12Ω typ (VBATT = 2.8V, IOUT = 10mA); 8.5Ω typ (VBATT = 4.5V, IOUT = 20mA) |
| VOUT, Normal Operating Mode | VCC – 0.02V typ (IOUT = 25mA); typically 260mV below VCC at the maximum 250mA output current |
| VOUT, Battery-Backup Mode | VBATT – 0.08V typ (VBATT = 2.0V, IOUT = 5mA); VBATT – 0.12V typ (VBATT = 2.8V, IOUT = 10mA); VBATT – 0.17V typ (VBATT = 4.5V, IOUT = 20mA) |
| Battery-Switchover Threshold | VBATT typ (power-down); VBATT + 0.05V typ (power-up) |
| Battery-Switchover Hysteresis | 50mV typ |
| Switchover Conditions | VCC below reset threshold AND VCC below VBATT |
| Battery Switch Topology | OUT connects to BATT through two internal series PMOS switches (facilitates UL approval) |
| Backup Source Compatibility | MaxCap®, SuperCap® (e.g., 0.47F) and conventional batteries; VBATT may exceed VCC |
| BATT ON Output | High: 2.0V min / 2.7V typ (VCC = 0V, ISOURCE = 0.1mA, VBATT = 2.8V); Low: 0.4V max (ISINK = 3.2mA); drives an external PNP/PMOS pass transistor for IOUT above 250mA |
| CHIP-ENABLE (CE) GATING – RAM WRITE PROTECTION | |
| CE IN to CE OUT Propagation Delay | 2ns typ, 8ns max (VCC = 5V, CLOAD = 50pF, 50Ω driver) |
| CE IN to CE OUT Resistance (enabled mode) | 75Ω typ, 150Ω max |
| CE IN Leakage Current (disabled mode, MR = 0V) | ±1µA max |
| RESET to CE OUT Delay (VCC falling) | 28µs typ |
| CE OUT Output Voltage High (RESET active, disabled) | 3.5V min (VCC = 5V, MR = 0V) |
| CE OUT Short-Circuit Current (RESET active) | 17mA typ (VCC = 5V, CE OUT = 0V, MR = 0V) |
| CE OUT (disabled mode) | Actively pulled up to the higher of VCC or VBATT |
| POWER-FAIL COMPARATOR (PFI / PFO) | |
| PFI Input Threshold (VPFT) | 2.265V typ, input falling (2.200V to 2.330V); 2.285V typ, input rising (2.220V to 2.350V); nominal 2.275V detector |
| PFI Hysteresis | 20mV typ |
| PFI to PFO Delay | 14µs typ (power failing); 32µs typ (power restored) |
| PFI Leakage Current | ±0.005nA typ, ±40nA max |
| PFO Operation | Low when PFI < VPFT; valid for VCC ≥ 4V; external resistor divider allows monitoring of supplies other than +5V |
| MANUAL RESET INPUT (MR) | |
| MR Threshold | VIL = 0.8V max; VIH = 2.4V min |
| MR Pullup Current | 50µA min, 100µA typ, 200µA max (MR = 0V) |
| MR Minimum Pulse Width | 1µs |
| MR-to-RESET Propagation Delay | 170ns typ |
| MR Usage | Active-low with internal pullup; TTL/CMOS compatible; momentary switch to GND (no debounce required); supports diode-OR of multiple reset sources |
| BATTERY-OK COMPARATOR (BATT OK) | |
| BATT OK Threshold (VBOK) | 2.265V typ (2.200V min, 2.350V max) |
| BATT OK Hysteresis | 20mV typ |
| BATT OK Operation | High when VBATT exceeds threshold (backup battery OK); valid for VCC ≥ 4V |
| LOGIC OUTPUTS (RESET, RESET, LOW LINE, WDO, PFO, BATT OK) | |
| Output Low Voltage (VOL) | 0.4V max at ISINK = 3.2mA |
| Output High Voltage (VOH) | VCC – 1.5V min at ISOURCE = 5mA (RESET: VCC – 1.5V min at ISOURCE = 0.1mA, VCC – 0.1V typ) |
| Output Short-Circuit Current (typ) | RESET: 60mA sink / 1.6mA source; RESET: 60mA sink / 15mA source; LOW LINE: 28mA sink / 20mA source; WDO, PFO, BATT OK: 35mA sink / 20mA source |
| RESET Output Structure | Strong pulldown / relatively weak pullup – can be wire-OR connected; RESET (active-high) sources and sinks current – cannot be wire-OR connected |
| ABSOLUTE MAXIMUM RATINGS | |
| Input Voltage VCC, VBATT (w.r.t. GND) | -0.3V to +6V |
| Input Voltage, All Other Inputs | -0.3V to (VOUT + 0.3V) |
| Input Current, VCC | 1.0A peak / 500mA continuous |
| Input Current, IBATT | 250mA peak / 50mA continuous |
| Input Current, GND and All Other Inputs | 50mA |
| Continuous Power Dissipation (16-Pin Plastic DIP, TA = +70°C) | 842mW (derate 10.53mW/°C above +70°C) |
| Operating Temperature Range | 0°C to +70°C |
| Storage Temperature Range | -65°C to +160°C |
| Lead Temperature (soldering, 10s) | +300°C |
Applications
- Computers
- Controllers
- Intelligent Instruments
- Critical µP Power Monitoring
- Portable / Battery-Powered Equipment
Package Content
- 1 x MAX807LCPE Microprocessor Supervisory Circuit With Precision 4.675V Voltage Monitoring 20mA/250mA DIP-16