CN207098587U - A kind of power protecting circuit based on MAX14586 chips - Google Patents

Abstract

It the utility model is related to a kind of power protecting circuit based on MAX14586 chips,OVLO control circuits are concatenated by resistance R24 1 end with resistance R25 2 ends,Two IN ends and connect in MAX14586 chips,Two OUT terminals simultaneously connect,GND ends are grounded,Power filtering unit is by electric capacity C240,C220 and 1 end for meeting rear tandem electric inductance coil FB5,2 ends are grounded,Electric capacity C16,C34 and 2 ends for meeting rear 1 end tandem electric inductance coil FB5,2 ends that integrated circuit is connected as resistance R24 in OVLO control circuits are connected for input with the IN ends of MAX14586 chips,1 end is connected with the OVLO ends of MAX14586 chips,MAX14586 chips OUT terminal connection electric capacity C240,Electric capacity C34 1 end is output end.The chip that rear end is protected when input voltage is excessive is had the technical effect that, the highest protection reachable+36V of voltage, by soft start, surge current is reduced, starts stabilization in 15 milliseconds.

Description

A kind of power protecting circuit based on MAX14586 chips

Technical field

It the utility model is related to a kind of power protecting circuit, more particularly to a kind of power protection based on MAX14586 chips Circuit.

Background technology

Power protecting circuit has a variety of forms of protection, wherein, including input over under-voltage protection circuit, output overvoltage/undervoltage guarantor Protection circuit, output overcurrent protection circuit, output short circuit protection circuit etc., it is substantially to small voltage overvoltage crowbar, at present We can reach the demand of 36V excessive voltage protection circuit to protection voltage, has put on the agenda and.For example, airborne reception Machine, which is powered, needs the voltage protection requirement of 28V even more highs；Prevent airborne anti-interference antenna input voltage higher than 28V damage equipment Deng.

The content of the invention

In view of the problem of prior art is present and actual needs, the utility model provide one kind and are based on MAX14586 chips Power protecting circuit, this circuit belongs to power conversion circuit, is designed using isolated gate FET (MOSFET), using partly leading The electroacoustic effect in body surface face is operated, by controlling outside input resistance to control OVLO door input values, to set overvoltage protection Numerical value, concrete technical scheme are a kind of power protecting circuits based on MAX14586 chips, including OVLO control circuits, MAX14586 chips, power filtering unit, it is characterised in that：OVLO control circuits are by resistance R24 1 end and resistance R25 2 ends Concatenation forms, and hinders R25 1 end ground connection, two IN ends and connects, two OUT terminals and connects, GND ends ground connection, electricity in MAX14586 chips Source filter unit is by electric capacity C240, C220 and connects rear 1 end tandem electric inductance coil FB5 1 end, 2 ends ground connection, and electric capacity C16, C34 are simultaneously Rear 1 end tandem electric inductance coil FB5 2 ends, 2 ends ground connection is connect, integrated circuit is connected as 2 ends of resistance R24 in OVLO control circuits It is connected for input with the IN ends of MAX14586 chips, 1 end is connected with the OVLO ends of MAX14586 chips, MAX14586 chips The electric capacity C240 of OUT terminal connection power filtering unit 1 end, the electric capacity C34 of power filtering unit 1 end is output end.This hair Bright has the technical effect that, realizes the chip that rear end is protected when input voltage is excessive, prevents destructive loss, highest protection Reachable+the 36V of voltage, by soft start, surge current is reduced, starts stabilization in 15 milliseconds.

Brief description of the drawings

Fig. 1 is circuit structure diagram of the present utility model.

Embodiment

As shown in figure 1, a kind of power protecting circuit based on MAX14586 chips, including OVLO control circuits, MAX14586 chips, power filtering unit, OVLO control circuits control the electricity of overvoltage protection by controlling between resistance ratio Pressure value, the processing of MAX14586 chip internal circuits, mainly set internal OVLO threshold values and realize excessively stream heat shutoff etc., power supply filter Wave circuit filters out the clutter with bypass circuit, makes power supply signal purer.

OVLO control circuits are concatenated with resistance R25 2 ends by resistance R24 1 end and formed, and hinder R25 1 end ground connection, In MAX14586 chips two IN ends and connect, two OUT terminals and connect, GND ends ground connection, power filtering unit by electric capacity C240, C220 simultaneously connects rear 1 end tandem electric inductance coil FB5 1 end, 2 ends ground connection, and electric capacity C16, C34 simultaneously meet rear 1 end tandem electric inductance coil FB5 2 ends, 2 ends ground connection, integrated circuit is connected as 2 ends of resistance R24 in OVLO control circuits as input and MAX14586 chips The connection of IN ends, 1 end be connected with the OVLO ends of MAX14586 chips, MAX14586 chips OUT terminals connects power filtering unit Electric capacity C240 1 end, the electric capacity C34 of power filtering unit 1 end is output end.

Overvoltage protection magnitude of voltage (the V of OVLO control circuits_{IN_OLV0}) establishing method be Wherein, V_OVLOFor the internal threshold voltage (about 7V ± 29%) of MAX14586 chips, R₂₄=1M Ω, protected by desired overvoltage Shield value can calculate R in circuit₂₅Value；MAX14586 chips provide small-sized 8 pin TDFN encapsulation, are sealed with naked pad Dress, the threshold voltage for being operated in -40 DEG C to+85 DEG C extension level temperature ranges is 7V representative values, the continuous current ability for having 3A, 40m Ω (representative value) n-channel MOSFET switch；Power filtering unit can substantially filter out electricity by capacitive bypass and magnetic bead filtering Noise signal in source signal, it can effectively prevent noise signal from influenceing the work of other chips.

Embodiment one

A kind of power protecting circuit based on MAX14586 chips is accessed into receiver voltage input end, the OVLO of the circuit Resistance R24 2 ends and resistance R25 1 end shunt-wound capacitance C1 are followed by external power supply in control circuit, during work, circuit input+ 5V operating voltages, pure+5V operating voltages are exported, be effectively protected receiver power supply power supply unit, and can provide pure + 5V power supply signals, using overvoltage protector MAX14586, there is the inside of low 48m Ω (representative value) conducting resistance (RON) FET and error protection voltage low-voltage system, which provide, is up to+36V input voltages, and more than overvoltage threshold, internal FET is closed, to prevent Stop loss and badly want protection element.The voltage and the optional non-essential resistances of 20V of any 4V between overvoltage protection threshold is adjustable.With For the input of OVLO doors less than the setting selection of outside OVLO gate voltages, equipment automatically selects internal accurate stroke threshold value.

Claims (1)

1. a kind of power protecting circuit based on MAX14586 chips, including the filter of OVLO control circuits, MAX14586 chips, power supply Ripple unit, it is characterised in that：OVLO control circuits are concatenated with resistance R25 2 ends by resistance R24 1 end and formed, and the 1 of resistance R25 End ground connection, two IN ends and connect, two OUT terminals and connect, GND ends ground connection in MAX14586 chips, power filtering unit is by electric capacity C240, C220 simultaneously connect rear 1 end tandem electric inductance coil FB5 1 end, 2 ends ground connection, and electric capacity C16, C34 simultaneously connect rear 1 end tandem electric inductance line FB5 2 ends, 2 ends ground connection is enclosed, 2 ends that integrated circuit is connected as resistance R24 in OVLO control circuits are input and MAX14586 The IN ends connection of chip, 1 end are connected with the OVLO ends of MAX14586 chips, MAX14586 chips OUT terminal connection power filter list The electric capacity C240 of member 1 end, the electric capacity C34 of power filtering unit 1 end is output end.