|
|
PDF HV9912 Data sheet ( Hoja de datos )
| Número de pieza | HV9912 | |
| Descripción | Switch-Mode LED Driver IC | |
| Fabricantes | Microchip | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de HV9912 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
HV9912
Switch-Mode LED Driver IC with High Current Accuracy
and Hiccup Mode Protection
Features
• Switch-mode Controller for Single-switch Drivers:
- Buck
- Boost
- Buck-boost
- SEPIC
• Works with High-side Current Sensors
• Closed-loop Control of Output Current
• High Pulse-Width Modulation (PWM) Dimming
Ratio
• Internal 90V Linear Regulator (can be extended
using external Zener Diodes)
• Internal 2% Voltage Reference (0°C < TA < 85°C)
• Constant Frequency or Constant Off-time
Operation
• Programmable Slope Compensation
• Linear and PWM Dimming
• +0.2A/–0.4A Gate Driver
• Hiccup Mode Protection for both Short-circuit and
Open-circuit Conditions
• Output Overvoltage Protection
• Synchronization Capability
• Pin Compatible with HV9911
Applications
• RGB Backlight Applications
• General LED Lighting Applications
• Battery-powered LED Lamps
General Description
HV9912 is an LED driver IC designed to control
single-switch PWM converters (buck, boost,
buck-boost and SEPIC) in a Constant Frequency or
Constant Off-time mode. The controller uses a peak
Current Mode control scheme with programmable
slope compensation and includes an internal
transconductance amplifier to control the output current
in closed loop, enabling high output current accuracy.
In the case of buck and buck-boost converters, the
output current can be sensed using a high-side current
sensor like the HV7800. In the Constant Frequency
mode, multiple HV9912 ICs can be synchronized with
each other or with an external clock, using the SYNC
pin. Programmable MOSFET current limit enables
current limiting during Input Undervoltage and Output
Overload conditions. The IC also includes a 0.2A
source and 0.4A sink gate driver that makes the
HV9912 suitable for high-power applications. An
internal 90V linear regulator powers the IC, eliminating
the need for a separate power supply for the IC. The IC
also provides a FAULT output, which can be used to
disconnect the LEDs in case of a Fault condition using
an external disconnect FET. HV9912 also provides a
TTL-compatible, low-frequency PWM dimming input
that can accept an external control signal with a duty
ratio of 0-100% and a frequency of up to a few kilohertz.
The HV9912 includes hiccup protection from both short
and open circuits, with automatic recovery after the
Fault condition is cleared.
The HV9912 is a pin-compatible replacement for
HV9911. It can be used with existing HV9911 designs,
which have input voltages of less than 90V, by
changing ROVP1, ROVP, and RT.
Package Type
16-lead SOIC
(Top View)
See Table 2-1 for pin information.
VIN 1
VDD 2
GATE 3
GND 4
CS 5
SC 6
RT 7
SYNC 8
16 FDBK
15 IREF
14 COMP
13 PWMD
12 OVP
11 FAULT
10 REF
9 CLIM
2016 Microchip Technology Inc.
DS20005583A-page 1
1 page  
HV9912
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: TA = 25°C and VIN = 12V unless otherwise specified.
Parameters
Sym.
Min. Typ. Max. Units
Conditions
Load Regulation of Reference
Voltage
VREFLOAD
0
REF bypassed with a 0.1 µF
—
10
mV
capacitor to GND;
IREF = 0 µA–500 µA;
PWMD = GND
PWM DIMMING
PWMD Input Low Voltage
PWMD Input High Voltage
PWMD Pull-down Resistance
GATE
VPWMD(LO)
VPWMD(HI)
RPWMD
—
2
50
— 0.8
——
100 150
V Note 2
V Note 2
kΩ VPWMD = 5V
GATE Short-circuit Current
GATE Sinking Current
GATE Output Rise Time
GATE Output Fall Time
OVERVOLTAGE PROTECTION
ISOURCE 0.2 — —
ISINK
0.4 — —
TRISE
— 50 85
TFALL
— 25 45
A VGATE = 0V
A VGATE = VDD
ns CGATE = 1 nF
ns CGATE = 1 nF
Overvoltage Rising Trip Point
Overvoltage Hysteresis
CURRENT SENSE
VOVP,RISING
VOVP,HYST
4.75
—
5 5.25
0.5 —
V OVP rising
V OVP falling
Leading Edge Blanking
TBLANK
100
100
— 280
— 330
ns 0°C < TA < +85°C
–40°C < TA < +125°C
COMP = VDD; CLIM = REF;
Delay to Output of COMP Comparator TDELAY1
—
— 200
ns CSENSE = 0 mV to 600 mV
(step up)
COMP = VDD; CLIM = 300 mV;
Delay to Output of CLIMIT Comparator TDELAY2
—
— 200
ns CSENSE = 0 mV to 400 mV
(step up)
Comparator Offset Voltage
VOFFSET
–10
—
10
mV
INTERNAL TRANSCONDUCTANCE OPAMP
Gain Bandwidth Product
GBW
—
1
—
MHz
75 pF capacitance at OP pin
(Note 3)
Open-loop DC Gain
Input Common Mode Range
Output Voltage Range
Transconductance
Input Offset Voltage
Input Bias Current
OSCILLATOR
AV
VCM
VO
gM
VOFFSET
IBIAS
60 — — dB Output open
–0.3 —
3
V Note 3
0.7 — 6.75 V Note 3
450 550 650 µA/V
–5 — 5 mV
— 0.5 1
nA Note 3
Oscillator Frequency
fOSC1
fOSC2
99 106 118 kHz RT = 500 kΩ (Note 2)
510 580 650 kHz RT = 96 kΩ (Note 2)
Maximum Duty Cycle
DMAX
87 — 93 %
Note 1: See Section 3.3 “Minimum Input Voltage at VIN Pin” for the minimum input voltage.
2: The specifications which apply over the full operating temperature range at
–40°C < TA < +85°C are guaranteed by design and characterization.
3: For design guidance only
2016 Microchip Technology Inc.
DS20005583A-page 5
5 Page 
If the output short-circuit exists before the PWMD
signal goes high, the total detection can be computed
as shown in Equation 3-7:
EQUATION 3-7:
tdetect = tblank SCmax + tdelaymax 900 + 250
1150nsmax
If the short-circuit occurs when the PWMD signal is
already high, the time to detect is determined through
Equation 3-8:
EQUATION 3-8:
tdetect1 = tdelaymax 250nsmax
3.13 Hiccup Timer
HV9912 reuses the compensation network on the
COMP pin to create a timer which is activated upon
startup or when a detected Fault has been cleared.
When a Fault is detected (either open-circuit or
short-circuit) or upon startup, the COMP pin is
disconnected from the gM amplifier and the GATE and
FAULT pins are pulled low, disabling the LED driver.
When the Fault has cleared, a 5 µA current source is
activated which pulls the COMP network up to 5V.
Once the voltage at the COMP network reaches 5V, the
5 µA sourcing current is disconnected and a 5 µA
sinking current is activated which pulls the COMP pin
low. When the voltage at the COMP pin reaches 1V, the
sinking current is disconnected and the gM amplifier is
reconnected to the COMP pin. The FAULT pin goes
high and the GATE pin would be allowed to switch. The
closed-loop control then takes over the control of the
LED current.
3.14 Startup Condition
The startup waveforms are shown in Figure 3-2.
Assuming a pole-zero R-C network at the COMP pin
(series combination of RZ and CZ in parallel with CC),
the start-up delay time can be approximately computed
as shown in Equation 3-9.
EQUATION 3-9:
tdelay tPOR + CC + CZ 5--9----V--A--
HV9912
This equation assumes that the voltage drop across RZ
can be neglected compared to the voltage swing at the
COMP pin, which is true in most cases (RZ < 100 kΩ).
The POR time (tPOR) for the HV9912 is 10 μs.
VIN
POR
COMP
5.0V
Pull-up
with 5.0µA
Pull-down
with 5.0µA Gm control
1.0V
FLT
tPOR
tDELAY
FIGURE 3-2:
Waveforms during Startup.
3.15 Fault Condition
In the case of a Fault condition (either open-circuit or
short-circuit), the same sequence is repeated, and the
only difference is that the COMP pin voltage does not
start from zero but from its Steady-state condition.
3.16 Short-Circuit Protection
When a Short-circuit condition is detected (output
current becomes higher than twice the Steady-state
current), the GATE and FAULT outputs are pulled low.
As soon as the disconnect FET is turned off, the output
current goes to zero and the Short-circuit condition
disappears. At this time, the hiccup timer is started.
(See Figure 3-3.) Once the timing is complete, the
converter attempts to restart. If the Fault condition still
persists, the converter shuts down and goes through
the cycle again. If the Fault condition is cleared due to
a momentary output short, the converter will start
regulating the output current normally. This allows the
LED driver to recover from accidental shorts without
having to reset the IC.
The hiccup time will depend on the Steady-state
voltage of the COMP pin (VCOMP). This is typically in
the range of 3V–4V. The hiccup time can be
approximately computed with Equation 3-10.
2016 Microchip Technology Inc.
DS20005583A-page 11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet HV9912.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| HV9910 | Universal High Brightness LED Driver |  Supertex |
| HV9910B | Universal High-Brightness LED Driver | Microchip |
| HV9910B | Universal High Brightness LED Driver | Supertex |
| HV9910C | Universal High-Brightness LED Driver | Microchip |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |