Electronic Components Datasheet Search |
|
UC3625DWG4 Datasheet(PDF) 9 Page - Texas Instruments |
|
UC3625DWG4 Datasheet(HTML) 9 Page - Texas Instruments |
9 / 25 page 0.001 0.01 0.1 100Hz 1kHz 10kHz 100kHz 1MHz µ µ µ µ µ UC1625 UC2625 UC3625 www.ti.com SLUS353C – NOVEMBER 2003 – REVISED JUNE 2013 Terminal Functions (continued) TERMINAL I/O DESCRIPTION NAME NO. Any time that VCC drops below threshold or the sensed current exceeds the over- current threshold, the soft-start latch is set. When set, it turns on a transistor that pulls down on SSTART. Normally, a capacitor is connected to this pin, and the transistor will completely discharge the capacitor. A comparator senses when the NPN transistor has completely discharged the capacitor, and allows the soft-start latch to clear when the fault is removed. When the fault is removed, the soft-start capacitor charges from the on-chip current source. SSTART clamps the output of the error amplifier, not allowing the error amplifier SSTART 24 output voltage to exceed SSTART regardless of input. The ramp on RC-OSC can be applied to PWM In and compared to E/A OUT. With SSTART discharged below 0.2 V and the ramp minimum being approximately 1.0 V, the PWM comparator keeps the PWM latch cleared and the outputs off. As SSTART rises, the PWM comparator begins to duty-cycle modulate the PWM latch until the error amplifier inputs overcome the clamp. This provides for a safe and orderly motor start-up from an off or fault condition. A 51-k Ω resister is added between VREF and SSTART to ensure switching. Any change in the H1, H2, or H3 inputs loads data from these inputs into the position sensor latches. At the same time data is loaded, a fixed-width 5-V pulse is triggered on TACH-OUT. The average value of the voltage on TACH-OUT is directly proportional to speed, so this output can be used as a true tachometer for speed feedback with an external filter or averaging circuit which usually consists of TACH-OUT 20 a resistor and capacitor. Whenever TACH-OUT is high, the position latches are inhibited, such that during the noisiest part of the commutation cycle, additional commutations are not possible. Although this effectively sets a maximum rotational speed, the maximum speed can be set above the highest expected speed, preventing false commutation and chatter. This device operates with supplies between 10 V and 18 V. Under-voltage lockout keeps all outputs off below 7.5 V, insuring that the output transistors never turn on VCC 19 until full drive capability is available. Bypass VCC to ground with an 0.1- μF ceramic capacitor. Using a 10- μF electrolytic bypass capacitor as well can be beneficial in applications with high supply impedance. This pin provides regulated 5 V for driving Hall-effect devices and speed control circuitry. VREF reaches 5 V before VCC enables, ensuring that Hall-effect devices VREF 2 powered from VREF becomes active before the UC3625 drives any output. Although VREF is current limited, operation over 30 mA is not advised. For proper performance VREF should be bypassed with at least a 0.1- μF capacitor to ground. TYPICAL CHARACTERISTICS Oscillator Frequency Tachometer on Time vs vs COSC and ROSC RT and CT Figure 2. Figure 3. Copyright © 2003–2013, Texas Instruments Incorporated Submit Documentation Feedback 9 Product Folder Links: UC1625 UC2625 UC3625 |
Similar Part No. - UC3625DWG4 |
|
Similar Description - UC3625DWG4 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |