HV9912 Supertex, Inc., HV9912 Datasheet
HV9912
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HV9912 Summary of contents
Page 1
... TTL compatible, low-frequency PWM dimming input that can accept an external control signal with a duty ratio of 0-100% and a frequency few kilohertz. The HV9912 includes hiccup protection from both short and open circuits, with automatic recovery after the fault condition is cleared. ...
Page 2
... CCCCCCCCC AAA *May be part of top marking 16-Lead SOIC (NG < T < + otherwise the specifi cations are at A Max Units Conditions input voltage 1.5 mA PWMD connected to GND V = 9.0 - 90V, 8. PWMD connected to GND 7 rising falling DD HV9912 Preliminary ...
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... HV9912 Preliminary < T < +85 C, otherwise the specifi cations are at A Units Conditions REF bypassed with a 0.1µF V capacitor to GND; I REF PWMD = GND REF bypassed with a 0.1µF mV capacitor to GND; I REF V = 7.25 – 12V; PWMD = GND DD REF bypassed with a 0.1µF mV capacitor to GND ...
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... PWMD = 400mA; DD REF 250 ns FDBK step from 0 to 900mV; FAULT goes from high to low 300 ns 330pF capacitor at FAULT pin 300 ns 330pF capacitor at FAULT pin 700 ns --- - µA --- 100 µA --- 2 50µ SLOPE SC O < +85 C are guaranteed by design and characterization. A HV9912 = 1.0kΩ ...
Page 5
... HV9911. Linear Regulator The HV9912 can be powered directly from its VIN pin that withstands a voltage up to 90V. When a voltage is applied at the VIN pin, the HV9912 tries to maintain a constant 7.75V (typ) at the VDD pin. The regulator also has a built in under- 5 HV9912 ...
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... In these circumstances recom- mended that the input voltage be kept higher than VIN Reference HV9912 includes a 2% accurate, 1.25V reference, which can be used as the reference for the output current as well as to set the switch current limit. The reference is buffered so that it can deliver a maximum of 500µ ...
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... SLOPE Current Sense The current sense input of the HV9912 includes a built in 100ns (minimum) blanking time to prevent spurious turn off due to the initial current spike when the FET turns on. The HV9912 includes two high-speed comparators - one is ...
Page 8
... To prevent this false shut- down, an R-C fi lter was used at the FDBK pin to fi lter this spike. To prevent these false triggering in the HV9912, there is a built-in 500ns blanking network for the short circuit compara- tor, which eliminates the need for the external R-C low pass fi ...
Page 9
... FLT signal goes high. This causes a short circuit to be detected and the HV9912 will go into short circuit protec- tion. This behavior continues till the output voltage becomes lower than the LED string voltage, at which point no fault will be detected and normal operation of the circuit will com- (Eqn ...
Page 10
... Output Current COMP overcome this in the HV9912, the minimum output of the gain stage is limited to 125 ~ 250mV, allowing the IREF pin to be pulled all the way to 0V without triggering the short cir- cuit comparator. Note: Since this control peak current mode controller, pulling the IREF pin to zero will not cause the LED current to become zero ...
Page 11
... This pin provides the over voltage protection for the converter. When the voltage at this pin exceeds 12 OVP 5V, the gate output of the HV9912 is turned off and FLT goes low. The IC will turn on when the voltage at the pin goes below 4.5V. When this pin is pulled to GND (or left open), switching of the HV9912 is disabled. When an external ...
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... JEDEC Registration MS-012, Variation AC, Issue E, Sept. 2005. Drawings not to scale. (The package drawing(s) in this data sheet may not refl ect the most current specifi cations. For the latest package outline information go to http://www.supertex.com/packaging.html.) Doc.# DSFP-HV9912 NR092607 Seating ...