Boost Type LED Driver with 4-Channel Current Source AP3064
Preliminary Datasheet
General Description
The AP3064 is a high efficiency boost controller with
4-string current sources for driving WLED backlight.
It operates over a wide input voltage range from 4.5V
to 33V.
The current of 4 strings are simply programmed from
20mA to 220mA with an external resistor. The
current matching between each string is 1.5% (Typ).
Its operating frequency can be adjusted from 0.1MHz
to 1MHz.
The AP3064 features cycle-by-cycle current limit,
soft-start, under voltage lockout (UVLO) protection,
programmable OVP, over temperature protection
(OTP), open/short LED protection, V
short/Schottky diode open protection and Schottky
Diode short-circuit protection.
The AP3064 is available in SOIC-16, PSOP-16,
DIP-16 and QFN-4×4-16 package s.
OUT
Features
• Input Voltage Range: 4.5V to 33V
• Drives up to 4 Strings in Parallel, 220mA per
String
Boost Type LED Driver with 4-Channel Current Source AP3064
Pin Description
Pin Number
SOIC-16
/PSOP-16
1 1 3 CH4
2 3 5 ISET
3 2 4 OVP
4 4 6 RT Frequency control pin
5 5 7
6 6 8
7 7 9 OUT
8 8 10 VCC
9 9 11 VIN
10 10 12 STATUSLED operation status output
DIP-16
QFN-
4×4-16
Pin
Name
EN
CS
Function
LED current sink 4. Leave the pin open
directly if not used
LED current setting pin. The corresponding
maximum current of all 4 strings is set through
connecting a resistor from this pin to GND
Over voltage protection pin. When the OVP
pin voltage exceeds 2.0V, the OVP is triggered
and the power switch is turned off. When the
OVP pin voltage drops below hysteresis
voltage, the OVP is released and the power
switch will resume normal operation
ON/OFF control pin. Forcing this pin above
2.4V enables the IC while below 0.5V shuts
down the IC. When the IC is in shutdown
mode, all functions are disabled to decrease
the supply current below 3µA
Power switch current sense input
Boost converter power switch gate output.
This pin output high voltage (5V/VIN-0.5V) to
drive the external N-MOSFET
5V linear regulator output pin. This pin should
be bypassed to GND (recommend to connect
with GND pin) with a ceramic capacitor
Supply input pin. A capacitor (typical 10
should be connected between the V
GND to keep the DC input voltage constant
and
IN
F)
11 11 13 COMP Soft-start and control loop compensation
PWM dimming control pin.
12 12 14 DIM
13 13 15 CH1
14 14 16 CH2
15 15 1 GND Ground
16 16 2 CH3
Adding a PWM signal to this pin to control
LED dimming. If not used, connect it to the
high level
LED current sink 1. Leave the pin open
directly if not used
LED current sink 2. Leave the pin open
directly if not used
LED current sink 3. Leave the pin open
directly if not used
Boost Type LED Driver with 4-Channel Current Source AP3064
Absolute Maximum Ratings (Note 1)
Parameter Symbol Value Unit
Input Voltage
CH1 to CH4 Voltage
EN Pin Voltage
VCC Pin Voltage
CS Pin Voltage
COMP Pin Voltage
ISET Pin Voltage
OUT Pin Voltage
OVP Pin Voltage
RT Pin Voltage
STATUS Pin Voltage
DIM Pin Voltage
GND Pin Voltage
V
V
V
VCC
V
V
COMP
V
V
V
V
V
STATUS
V
V
IN
CH
EN
CS
ISET
OUT
OVP
RT
DIM
GND
SOIC-16 100
Thermal Resistance (Junction to
Ambient, Free Air, No Heatsink)
θ
JA
PSOP-16 50
DIP-16 85
QFN-4×4-1655
Operating Junction Temperature
Storage Temperature
T
J
T
STG
Lead Temperature
T
(Soldering, 10sec)
LEAD
ESD (Machine Model) 200 V
ESD (Human Body Model) 2000 V
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.
Note 2: Negative CS 100ns Transient maximum rating voltage reach to -0.4V.
-0.3 to 42 V
-0.3 to 65 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 7 V
-0.3 to 0.3 V
ºC/W
150 ºC
-65 to 150 ºC
260 ºC
Recommended Operating Conditions
Parameter Symbol Min Max Unit
Input Voltage V
IN
Operating Frequency fO 0.1 1 MHz
LED Channel Voltage V
LED Channel Current I
PWM Dimming Frequency f
Boost Type LED Driver with 4-Channel Current Source AP3064
Application Information
1. Enable
The AP3064 is enable when the voltage to EN is greater
than approximately 2.4V, disabled when lower than
0.5V.
2. Frequency Selection
An external resistor RT, placed between RT pin and
GND, can be used to set the operating frequency. The
operating frequency ranges from 100kHz to 1MHz.
The high frequency operation optimizes the r egulator
for the smallest-sized component application, while
low frequency operation can help to reduce switch
loss. The approximate operating frequency can be
expressed as below:
OSC
][
MHzf
52
=
RT
][
Ω
KR
3. LED Current Setting
The maximum LED current per channel can be
adjusted up to 180mA via ISET pin. When ≥180mA
current is needed in application, two or more
channels can be paralleled to provide larger drive
current. Connect a resistor R
and GND to set the reference current I
current can be expressed as below:
1200
][
=
mAI
LED
ISET
][
Ω
KR
between ISET pin
ISET
SET
. The LED
4. Dimming Control
Applying a PWM signal to DIM pin to adjust the
LED current, that means, the LED current of all
enabled channels can be adjusted at the same time
and the LED brightness can be adjusted from 1%×
I
CHX_MAX
level” period of PWM signal, the LED is turned on
and 100% of the current flows through LED, while
during the “low level” period of the PWM signal, the
LED is turned off and almost no current flows
through the LED, thus cha nging the average current
through LED and finally adjusting LED brightness.
The external PWM signal frequency applied to PWM
pin is allowed to be 100Hz or higher.
to 100%× I
CHX_MAX
. During the “high
5. Status Output
After IC is enabled, STATUS will output logic low if
any of the following conditions exists:
(1) Any String is Open
(2) LED Short Circuit Protection
(3) Shut Down Under Abnormal Condition
(4) Over Voltage Protection
(5) Over Temperature Protection
(6) Schottky Diode Short Protection
(7) V
Short/Open Schottky Diode Protection
OUT
6. Over Voltage Protection
The AP3064 integrates an OVP circuit. The OVP pin
is connected to the center tap of voltage-divider (R
and R
and GND. If the voltage on OVP pin exceeds 2.0V,
which may results from open loop or excessive
output voltage, all the functions of AP3064 will be
disabled with output voltage falling. The OVP
hysteresis is 250mV. The formulas of OVP can be
expressed as below:
V
) that placed between high voltage output
OV2
2.0V)R(R
×
=
OVP
OV2OV1
R
OV2
7. Over Current Protection
The AP3064 integrates an OCP circuit. The CS pin is
connected to the voltage-sensor (R
between the Drain of MOS and GND. If the voltage
on CS pin exceeds 0.54V, it is turned off immediately
and will not turn on until the next cycle begins.
) that placed
CS
8. LED Short-Circuit Protection
The AP3064 integrates an LED Short-circuit
protection circuit. If the voltage at any of the CH1-4
pins exceeds a threshold of approximately 7.3V
during normal operation, the corresponding str ing is
turned off and is latched off. Toggle V
reset the latch. LED short detecting logic priority is
lower than open LED and OVP logic. The LED short
detecting is triggered when 0.1V<V
dimming on mode, disabled when LED open occurs
until output voltage resumes to the regulated voltage.
Boost Type LED Driver with 4-Channel Current Source AP3064
Application Information (Continued)
9. LED Open-circuit Protection
The AP3064 integrates an LED Open-circuit
Protection circuit. When any LED string is open,
V
will boost up until the voltage at OVP pin
OUT
reaches an approximate 2.0V threshold. The IC will
automatically ignore the open string whose
corresponding pin voltage is less than 100mV and the
remaining string will continue operation. If all the
strings are open and the voltage at OVP reaches a
threshold of 2.0V, the MOSFET drive GATE will turn
off and IC will shut down and latch.
10. V
Short / Open Schottky Diode
OUT
Protection
The AP3064 monitors the OVP pin, if the OVP pin
voltage is less than 0.1V, MOSFET drive output will
turn off. This protects the converter if the output
Schottky diode is open or V
is shorted to ground.
OUT
11. Under Voltage Lockout
The AP3064 provides an under voltage lockout
circuit to prevent it from undefined status when
startup. The UVLO circuit shuts down the device
when V
200mV hysteresis, which means the device starts up
again when V
drops below 3.6V. The UVLO circuit has
CC
rise to 3.8V.
CC
12. Over Temperature Protection
The AP3064 features Over Temperature Protection, if
the junction temperature exceeds approximately
160ºC, the IC will shut down until the junction
temperature is less than approximately 140ºC. When
the IC is released from over temperature shutdown, it
will start a soft-start process.
13. Schottky Diode/Inductor Short Circuit Protection
The AP3064 features Schottky diode/inductor
short-circuit protection circuit. When CS pin voltage
exceeds 0.8V for greater than 16 switching clocks,
the IC will latch. The voltage of CS is monitored
after a short delay of LEB.
14. Shut Down under Abnormal Condition
The AP3064 features shutdown under abnormal
condition protection circuit. When OVP pin voltage
exceeds 3.2V, the IC will latch. Toggle EN to restart
the IC. This feature can be used for any other
protection to shut down the IC.