illustrate
The ZXS C410 is a voltage mode boost converter in a SOT23-6 package. Very good load and line regulation means that the variation in output voltage is typically less than 1% over the full supply range of the Li-Ion battery. Using high-efficiency Zetex switching transistors allows output voltages to be in the tens of volts, depending on the transistor chosen. The ZXSC 420 includes a low battery indicator. This works by indicating when the converter can no longer maintain a regulated output voltage rather than setting a preset threshold, thus making it suitable for various battery options and load currents.

Device Description All threshold voltages and internal currents have been released from a temperature compensated bandgap reference circuit with a reference voltage of 1.22V .
The dynamic drive output is either "low" or "high" depending on the input signal. In the high state, a 2.5mA current source (maximum drive voltage = VCC - 0.4V) drives the base tissue of the external transistor. In order for the external switching transistor to operate at optimum efficiency, both output states are started with short transient currents to rapidly discharge the base or gate of the switching transistor.
The S-switch circuit simultaneously starts to drop slowly. With an EOR detector, the battery can be used for the final end of discharge, with enough time to safely shut down.
The ZXSC420 switch circuit consists of two comparators comp1 and comp2, a gate u1, a monostable and a drive output, the drive output is normally "high"; the external switch transistor is turned on

rises in inductors, switching transistors, and external current sense resistors. This voltage is sensed at the input isense by the comparator comp2. Once the current sense voltage on the sense resistor exceeds 20mV, the comparator COMP2 triggers through the U1 gate to retrigger the monostable and shuts down
ZXSC410
Output driver stage for 2 µs. The inductor discharges to the application load. The charge cycle begins after 2 microseconds, causing the output voltage to rise. When the output voltage reaches its rated value and the input voltage to VFB exceeds 300mV, the monostable is forced "open" from COMP1 to the U1 gate until the feedback voltage drops below 300mV. The above actions continue to maintain the regulated EOR, the end-of-regulation detector EOR circuit is a retriggerable 120 microsecond monostable circuit that is retriggered by every down action of the comparator COMP1. Output EOR is "high" (high impedance, 100K to VCC) as long as it is regulated. Ignore brief dips in output voltage below 120 microseconds. If the output voltage falls below the rated value for more than 120 microseconds, the output EOR goes "low". This usually happens because the input voltage of the discharged battery drops slowly. Therefore, the output voltage will be

Application Information Switching Transistor Selection Switching transistor selection has a significant impact on conversion efficiency. For optimal performance, a bipolar transistor with low VCE (SAT) and high gain is required. The VCEO of the switching transistor is an important parameter. Because it can see the full output voltage when the transistor is turned off. Zetex Supersot 8482 ; transistor is ideal for this application.
S Chottky diode selection Like switching transistors, Schottky rectifier diodes have a significant impact on converter efficiency. This application should use a Schottky diode with low forward voltage and fast recovery time.
The diodes should be chosen such that the maximum forward current rating is greater than or equal to the maximum peak current in the inductor and the maximum reverse voltage is greater than or equal to the output voltage. The Zetex ZHCS series meets these needs.
Combination Setup To minimize the number of external components, Zetex recommends combining the Zx3CDBS1M832 of npn transistors and Schottky diodes in a 3mm x 2mm MLP package. This device is recommended for space critical applications.
Integrated circuits are also capable of driving MOSFETs. Zetex recommends combining the Zxmns3bm832 low threshold voltage N-channel MOSFET and Schottky diode in a 3mm x 2mm MLP package. This device is recommended for space critical applications.
Inductor Selection Inductor values must be selected to meet the performance, cost and size requirements of the overall solution.
The choice of inductance has an important influence on the performance of the converter. For applications where efficiency is critical, pipes with a resistance of 500m or less should be used.

Output Capacitor The output capacitor is a critical choice for the overall performance of the solution. They need to filter the output and provide load transient current. When selecting an output capacitor, there are three most important parameters: Capacitance, Iripple, and ESR. Select the capacitor value to meet load transient requirements. The capacitor IRiple rating must meet or exceed the current ripple of the solution.
The ESR of the output capacitor also affects the stability and transient performance of the loop. The capacitors selected for the solution and specified in the reference design are optimized to provide the best overall performance.
Input Capacitor Input capacitor voltage and rms current rating selection. Low ESR calcium carbide or tantalum capacitors are recommended. The Reference Designs section recommends capacitor values for optimal performance.
Also note that the ESR of the input capacitor is effectively in series with the input, so there is an efficiency penalty in the order of i.
Electron spin resonance.

Output Voltage Adjustment The ZXSC410/420 are adjustable output converters allowing maximum flexibility for the end user

Layout is critical for the circuit to operate in the most efficient manner in terms of electrical efficiency, thermal considerations, and noise.
For a "boost converter", there are four main current loops: the input loop, the power switch loop, the rectifier loop, and the output loop. The power supply that charges the input capacitors forms the input loop. The power switch loop is defined when q1 is "on", and current flows from the input through the inductor q1, rsense, and ground. When q1 is "off", the energy stored in the inductor is transferred through d1 to the output capacitor and load, forming the installer loop. When Q1 is off, the output capacitor provides the load, forming the output loop.
To optimize best performance, each of these loops is kept separate from each other and interconnected with short, thick traces that minimize parasitic inductance, capacitance, and resistance. Additionally, the rsense resistor should be connected with a minimum trace length between Q1's emitter lead and ground, again to minimize stray parasitics.

ZX S C410 as triple output TFT bias voltage average voltage=9V/180mA

ZX S C410 as triple output TFT bias voltage average voltage=9V/180mA

A 10ms delay between AVDD power-up and von power-up can be achieved by adding the circuit below to the converter's LCD bias output (von). The circuit works by turning on the PMOS transistor with a delay, which transmits to a delay of 10 milliseconds between the input and output of the circuit.
The delay is set by the RC time constants of R1 and C1. When the main system power is turned off, diode d1 releases the gate of the PMOS, guaranteeing the delay of each turn-on cycle