Datasheet MAX5902, MAX5903 (Maxim) - 8
| Manufacturer | Maxim |
| Description | +72V SOT23/TDFN Simple Swapper Hot-Swap Controllers |
| Pages / Page | 14 / 8 — +72V, SOT23/TDFN, Simple Swapper Hot-Swap Controllers. Turn-On and … |
| File Format / Size | PDF / 342 Kb |
| Document Language | English |
+72V, SOT23/TDFN, Simple Swapper Hot-Swap Controllers. Turn-On and Turn-Off Delays. MAX5902/MAX5903. Thermal Shutdown
Model Line for this Datasheet
- MAX5902AAETT+ MAX5902AAETT+T MAX5902AAEUT MAX5902AAEUT+ MAX5902AAEUT+T MAX5902ABEUT MAX5902ABEUT+ MAX5902ABEUT+T MAX5902ACEUT MAX5902ACEUT+ MAX5902ACEUT+T MAX5902ACEUT+TG11 MAX5902ACEUT-T MAX5902LAETT+ MAX5902LAETT+T MAX5902LAEUT MAX5902LAEUT+ MAX5902LAEUT+T MAX5902LAEUT-T MAX5902LBEUT+ MAX5902LBEUT+T MAX5902LCETT+ MAX5902LCETT+T MAX5902LCEUT MAX5902LCEUT+ MAX5902LCEUT+T MAX5902NNETT+ MAX5902NNEUT MAX5902NNEUT+ MAX5902NNEUT+T
- MAX5903AAETT+ MAX5903AAETT+T MAX5903AAEUT+ MAX5903AAEUT+T MAX5903ABETT+ MAX5903ABETT+T MAX5903ABEUT+ MAX5903ABEUT+T MAX5903ACETT+ MAX5903ACETT+T MAX5903ACEUT+ MAX5903ACEUT+T MAX5903LAEUT+ MAX5903LAEUT+T MAX5903LBEUT+ MAX5903LBEUT+T MAX5903LCEUT+ MAX5903LCEUT+T MAX5903NNETT+ MAX5903NNETT+T MAX5903NNEUT+ MAX5903NNEUT+T
Text Version of Document
+72V, SOT23/TDFN, Simple Swapper Hot-Swap Controllers
HOT-SWAP CONTROLLER HOT-SWAP CONTROLLER +9V TO +72V MAX5902 MAX5903 47k MAX5902 Ω 100kΩ 5V LOGIC ON/OFF VS GND GND ON/OFF GND LOGIC CONTROL OF 3.3V OR LESS MAY BE CONNECTED GND DIRECTLY TO THE MAX5902/MAX5903. FOR 5V LOGIC CONTROL INSERT A SERIES 47kΩ RESISTOR AS SHOWN. Figure 5. Logic Control Figure 6. Defeating Undervoltage Lockout
Turn-On and Turn-Off Delays
and +72V use a resistor divider connected between VS After power is applied, or ON/OFF is released, there is and GND, with the center node of the divider connect-
MAX5902/MAX5903
a 150ms delay (tON) before the gate ramp is started. ed to ON/OFF. For example, use a 3kΩ resistor (R1 in This delay is also the automatic restart time delay. Figure 3) from ON/OFF to GND and calculate the other In the event of a circuit-breaker condition or an over- resistor, R2, using: temperature fault condition, the turn-off delay is less ⎛ V ⎞ UVLO than 4µs. An undervoltage condition must exist for at R2 = R 1 × − 1 ⎜ V ⎟ least 10ms (t ⎝ ON / OFF ⎠ OFF) before the MAX5902/MAX5903 turns off the external MOSFET. ON/OFF must be held low for at least 10ms (tOFF) before the MAX5902/MAX5903 where VUVLO is the desired lockout voltage, and turns off the external MOSFET. Turn-off delay minimizes VON/OFF is the ON/OFF reference threshold specified in spurious shutdowns due to noisy signals or momentary the Electrical Characteristics table (typically 1.26V). voltage spikes, as well as preventing accidental reset- Figure 3 shows an example circuit with VUVLO set for ting of the circuit-breaker latch (MAX5902L/MAX5903L). +18V. To defeat the UVLO simply connect a single
Thermal Shutdown
100kΩ resistor between ON/OFF and VS, as shown in Figure 6. A thermal shutdown feature helps protect the external MOSFET. If the die temperature of the MAX5902/
The Power-Good Output
MAX5903 exceeds +125°C, the MOSFET is turned off. The power-good output, PGOOD (PGOOD), is open- For accurate performance the MAX5902/MAX5903 drain and asserts when the external MOSFET is fully must be in close thermal contact with the external MOS- enhanced and VSD is less than the circuit-breaker FET. See the Layout Guidelines section for information. threshold (VCB). For versions without the circuit-breaker Due to the low power dissipation of the function (MAX5902N/MAX5903N), PGOOD (PGOOD) MAX5902/MAX5903, its junction temperature will typi- asserts when the external MOSFET is fully enhanced. cally be within a few degrees of the MOSFET. All ver- PGOOD sions of the MAX5902/MAX5903 automatically restart (PGOOD) deasserts within 4µs when a circuit- from a temperature fault when the junction temperature breaker event occurs or if the die temperature exceeds drops below +110°C. +125°C. PGOOD (PGOOD) deasserts if VS < VUVLO for longer than 10ms or ON/OFF is held low for longer than
Undervoltage Lockout
10ms. The MAX5902/MAX5903 turns off the external MOSFET The MAX5902 PGOOD is active-low and the MAX5903 if the magnitude of the input voltage is below the level PGOOD is active-high. Both are open-drain n-channel set by ON/OFF for longer than 10ms (tOFF). If ON/OFF MOSFETs with their sources connected to GND, and is left unconnected, the lockout voltage (VUVLO) can withstand up to +72V. defaults to 31.5V. VUVLO may also be set to any value within the power-supply range by using external resis- tors. To set the lockout voltage to a value between +9V
8 _______________________________________________________________________________________
HOT-SWAP CONTROLLER HOT-SWAP CONTROLLER +9V TO +72V MAX5902 MAX5903 47k MAX5902 Ω 100kΩ 5V LOGIC ON/OFF VS GND GND ON/OFF GND LOGIC CONTROL OF 3.3V OR LESS MAY BE CONNECTED GND DIRECTLY TO THE MAX5902/MAX5903. FOR 5V LOGIC CONTROL INSERT A SERIES 47kΩ RESISTOR AS SHOWN. Figure 5. Logic Control Figure 6. Defeating Undervoltage Lockout
Turn-On and Turn-Off Delays
and +72V use a resistor divider connected between VS After power is applied, or ON/OFF is released, there is and GND, with the center node of the divider connect-
MAX5902/MAX5903
a 150ms delay (tON) before the gate ramp is started. ed to ON/OFF. For example, use a 3kΩ resistor (R1 in This delay is also the automatic restart time delay. Figure 3) from ON/OFF to GND and calculate the other In the event of a circuit-breaker condition or an over- resistor, R2, using: temperature fault condition, the turn-off delay is less ⎛ V ⎞ UVLO than 4µs. An undervoltage condition must exist for at R2 = R 1 × − 1 ⎜ V ⎟ least 10ms (t ⎝ ON / OFF ⎠ OFF) before the MAX5902/MAX5903 turns off the external MOSFET. ON/OFF must be held low for at least 10ms (tOFF) before the MAX5902/MAX5903 where VUVLO is the desired lockout voltage, and turns off the external MOSFET. Turn-off delay minimizes VON/OFF is the ON/OFF reference threshold specified in spurious shutdowns due to noisy signals or momentary the Electrical Characteristics table (typically 1.26V). voltage spikes, as well as preventing accidental reset- Figure 3 shows an example circuit with VUVLO set for ting of the circuit-breaker latch (MAX5902L/MAX5903L). +18V. To defeat the UVLO simply connect a single
Thermal Shutdown
100kΩ resistor between ON/OFF and VS, as shown in Figure 6. A thermal shutdown feature helps protect the external MOSFET. If the die temperature of the MAX5902/
The Power-Good Output
MAX5903 exceeds +125°C, the MOSFET is turned off. The power-good output, PGOOD (PGOOD), is open- For accurate performance the MAX5902/MAX5903 drain and asserts when the external MOSFET is fully must be in close thermal contact with the external MOS- enhanced and VSD is less than the circuit-breaker FET. See the Layout Guidelines section for information. threshold (VCB). For versions without the circuit-breaker Due to the low power dissipation of the function (MAX5902N/MAX5903N), PGOOD (PGOOD) MAX5902/MAX5903, its junction temperature will typi- asserts when the external MOSFET is fully enhanced. cally be within a few degrees of the MOSFET. All ver- PGOOD sions of the MAX5902/MAX5903 automatically restart (PGOOD) deasserts within 4µs when a circuit- from a temperature fault when the junction temperature breaker event occurs or if the die temperature exceeds drops below +110°C. +125°C. PGOOD (PGOOD) deasserts if VS < VUVLO for longer than 10ms or ON/OFF is held low for longer than
Undervoltage Lockout
10ms. The MAX5902/MAX5903 turns off the external MOSFET The MAX5902 PGOOD is active-low and the MAX5903 if the magnitude of the input voltage is below the level PGOOD is active-high. Both are open-drain n-channel set by ON/OFF for longer than 10ms (tOFF). If ON/OFF MOSFETs with their sources connected to GND, and is left unconnected, the lockout voltage (VUVLO) can withstand up to +72V. defaults to 31.5V. VUVLO may also be set to any value within the power-supply range by using external resis- tors. To set the lockout voltage to a value between +9V
8 _______________________________________________________________________________________
