AP8804 DIODES | Alldatasheet
Document overview
- Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
- PDF pages: 9
Technical content
Features
- 100mV Maximum output saturation voltage
- TDFN small outline package
- 10% Output current tolerance
- 0 to 70°C Junction temperature range
- Available in “Green” Molding Compound (No Br, Sb) with lead free Finish/RoHS Compliant (Note1) Typical Application Circuit Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied, see EU Directive 2002/95/EC Annex Notes. Top View TDFN2020-6
6 OUT
1000:1 current gain block Linear Controller OUT I = 1000 IBIAS = 1000/RBIAS RBIAS 0.1V 1000:1 current gain block Linear Controller BIAS VCC GND 1.0V IOUT 1.8V 0.1V
Document number: DS32050 Rev. 2 - 5 2 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated Absolute Maximum Ratings Symbol Paramete r Rating Unit VCC Supply Voltage -0.3 to +8 (Relative to GND) V VOUT Output Voltage VBIAS Bias Input Voltage -0.3 to +0.3 (Relative to GND) V TJ Junction Temperature 150 °C TST Storage Temperature -65 to +150 °C Note: These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure. Operation at the absolute maximum rating for extended periods may reduce device reliability. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices. Recommended Operating Conditions Symbol Paramete r Min Max Unit VCC Supply Voltage 1.8 6 V IBIAS BIAS Input Current -0.33 0 mA IO Output Current 50 350 mA TA Operating Ambient Temperature Range 0 70 °C Package Thermal Data Thermal Resistance Package Unit Junction-to-Ambient, θJA TDFN2020-6 80 °C/W Junction-to-Case, θJC TDFN2020-6 20 Electrical Characteristics (Under Operating Conditions) VOUT = 0.2V, TA = 25°C (unless otherwise stated). All typical are at 25°C (FT = 0 to 70°C) Parameter Conditions TA Min Typ. Max Unit DC parameters Bias voltage VCC = 1.8V, RBIAS = 3.05kΩ2 25 900 1040 1200 mV FT 860 1240 Output current accuracy 3 VCC = 2.0V to 6V, VOUT = VCC – 1.8V, RBIAS = 4.1kΩ 25 225 250 275 mA Saturated output current tolerance 5 VCC = 2.0V, VOUT = 0.2V RBIAS = 3.05kΩ, IOUT = 350mA 25 15 % FT 20 VCC = 2.0V, VOUT = 0.5V RBIAS = 3.05kΩ IOUT = 350mA 25 10 % FT 15 VCC = 2.0V, VOUT = 0.15V RBIAS = 4.1kΩ, IOUT = 250mA 25 15 % FT 20 Current Gain (IOUT/IBIAS) 3, 4 VCC = 2V, VOUT = 0.2V, 50µA < IBIAS < 350µA 25 1000 Quiescent current VCC = 6V, RBIAS = Open Circuit FT 100 150 µA Supply current (Active) VCC = 2V, RBIAS = 3.05kΩ, VOUT = 0.5V FT 5.5 9 mA Output Leakage (Off) Vcc = 6V, RBIAS >= 2MΩ, VOUT = 6V 25 <1 10 uA Output Leakage (Disabled) Vcc = 0V, VOUT = 6V 25 <1 100 nA AC parameters Rise time (10% to 90%)5 VCC = 2.0V, VOUT = 0.5V, RBIAS = O/C to 3.05kΩ 0.2 µs Fall time (90% to 10%)5 RBIAS = 3.05kΩ to O/C 0.2 Propagation delay(low to high)5 VCC = 2.0V, VOUT = 0.5V, RBIAS = O/C to 3.05kΩ 0.4 Propagation delay(high to low)5 RBIAS = 3.05kΩ to O/C 0.2 Notes: 2. R BIAS connected to GND see Figure 1 3. All active output current measurements are pulsed tests of 8us duration, 10% duty cycle 4. See Typical Characteristics for a graph of Output current vs. RBIAS value 5. See Figure 2
Document number: DS32050 Rev. 2 - 5 4 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated Typical Characteristics 100 150 200 250 300 350 400 01234 5 6 V ( V ) I vs. V CC OUT C C I ( m A )OUT R_B= 20k R_B= 9. 7k R_B= 6. 8k R_B= 4. 1k R_B= 3. 0k
8 Pulse Test 10% Duty Cycle
S μ 100 150 200 250 300 350 400 0 5 10 15 20 25 R ( k O h m s )BIAS I v s . ROUT BIAS I ( m A )OUT V = 3 V , V = V - VCC OUT C C LED R_B = 4.1k 100 150 200 250 300 350 400 0 12 3 4 5 6 R_B = 3.0k V ( V ) I vs. V CC OUT CC I ( m A )OUT R_B = 4.1k R_B = 6.8k R_B = 9.7k R_B = 20k V = V V, T 2 5 C
8 S Pulse Test @ 10% Duty Cyc le
OUT CC LED A ° μ 100 150 200 250 300 350 V ( V )OUT I ( m A )OUT I vs. VOUT CC R_B = 20k R_B = 9.7k R_B = 6.8k R_B = 4.1k R_B = 3.0k 8 s Pulsed Test, 10% Duty Cycle CC OUT A ° μ
Document number: DS32050 Rev. 2 - 5 5 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated Typical Characteristics (Cont.) Channel 1 (Upper): V_Bias @ 0.5V/div Channel 2 (Lower): I_Out @ 100mA/div Timebase: 2us/div Pulse Response R_Bias 4.1k 0mA 0mA Channel 1 (Upper): V_Bias @ 0.5V/div Channel 2 (Lower): I_Out @ 20mA/div Timebase: 2us/div Pulse Response R_Bias 21.0k PIN Descriptions NAME I/O Pin # FUNCTION NC - 1 No connection. May be grounded or left floating. GND Power 2 GND or the most negative terminal of the LED Driver. Also carries the LED return current. BIAS I 3 The output of an internal voltage reference (1.0V approx.). Connect a resistor RBIAS from this pin to the external control input. The LED Driver amplifies the RBIAS resistor current by a factor of nominally1000. Open circuiting this pin or driving this pin to >1.25V will turn off the output of the AP8804. Avoid unnecessary stray capacitance at this pin, and connect RBIAS as close as possible to it. VCC Power 4 The supply input pin of the LED Driver. This pin supplies the internal circuitry of the IC which is typically 80uA + 2.5% of the LED output current. It is advisable to decouple this pin with a 100nF capacitor to GND. NC - 5 No connection. May be grounded or left floating. OUT O 6 The output of the LED Driver, normally connected to the cathode of the LED. The normal working range of this pin is 0.1V (0.1V above GND pin potential) to 6V. It is permissible for the voltage on this pin to be higher than V CC.
Document number: DS32050 Rev. 2 - 5 6 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated Applications Information Setting the Output Current The AP8804 is controlled by an input current at the BIAS pin. When an LED or load re sistance is connected between a positive supply and OUT, the load current IOUT is proportional to the input current at t he BIAS input of the AP8804. The current gain, AI is nominally -1000. The voltage at the BIAS pin is controlled to nominally +1.0V. The resistor RBIAS sets the input current according to the input voltage, VIN, as in Figure 3. Figure 3 Therefore the input voltage, VIN , determines the output current according to this equation: I OUT = AI * (VIN – VBIAS) / RBIAS if VIN ≤ VBIAS and IOUT = 0 if VIN ≥ VBIAS Note that these equations are approxim ate and a more accurate value of curr ent can be found using the graph of I OUT vs RBIAS. Select RBIAS to give the required IOUT. For example, if R BIAS = 3k, an input of 0V will give an output current of nominally 350mA, while an input of about +1.1V or greater will give an output current equal to the leakage value which is typically less than1µA. Driving the AP8804 The input current is approximately 1/RBIAS when the driven end of R BIAS is pulled to 0V or roughly output current divided by 1000. For a typical output current of up to about 300 mA, the input current will be 300µA or less. Hence a low level CMOS or open-dra in logic drive level is convenient to turn the LED on (logic LOW, 0V) and off (logic HIGH, 1V or greater). By connecting a switch to ground in series with R BIAS (see figure 3) the device can be turned on and off. Typical applications for this include LED dimming as well as data interface applications. An alternate way of turning the output of the AP8804 off is to dr ive the bias pin to greater than 1.1V. However direct drive t o this pin is not recommended. Stray capa citance at the BIAS pin must be avoi ded for stability and the resistor R BIAS should be placed close to the BIAS pin. The best method is to drive the input through the series resistor R BIAS as shown from a CMOS or open drain logic signal. Vcc pin quiescent current is typically 100uA and OUT pin leakage is typically less than 1uA when the device is turned off using the BIAS pin. BIAS pin controlled output switching times are less than 1us. A further means of disabling the device is to turn off the supply to the Vcc pin. In this state, assuming the LED anode is sti ll connected to the supply, the Vcc pin current is of course zero and the OUT pin leakage is typically less than 1nA. This method has the advantage of reducing the quiescent current from about 100µA to less than 1nA. When using this switching method, the time to settle to the desired current level may be several microseconds. 1000:1 current gain block Linear Controller BIAS V CC OUT GND 1.25V I OUT = 1000 I BIAS = 1000/R BIAS R BIAS 0.1V 1000:1 current gain block Linear Controller BIAS V CC OUT GND 1.0V I OUT = 1000 I BIAS BIAS R BIAS 1.8V 0.1V VIN
Document number: DS32050 Rev. 2 - 5 7 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated PCB Layout and Supply Conditioning For a satisfactory pulse shape and AC stability, attention shou ld be given to power supply decoupling. Connect a 0.1µF to 1µF X7R ceramic capacitor from Vcc to the common ground plane clos e to the Vcc pin. Position the capacitor close to the V CC pin and use local vias to ground the capacitor. Additional ground vias should be placed as close as possible to the central paddle connection for the sake of both the pulse performance and therma l heat-sinking. The ground plane is also required to minimize undesired common-impedance coupling between input and output. Excessive stray capacitance at the BIAS pin affects stability. It is sufficient to place the input bias resistor close to the BIAS pin to minimize the PCB trace capacitance to ground. The AP8804 has been designed to drive the cathode of a low voltage LED which has the anode connected to the same node as VCC pin. Alternatively the anode may be connected to a higher voltage than V CC within the limits given. However best LED current regulation will be obtained when the anode is connected to VCC. Power Dissipation and Operating Temperature Although the performance of the AP8804 is not significantly affected by junction tem perature, excessive power dissipation does affect the target output current. The typi cal variation of I_Out with power dissipation is approximately +0.065%/mW. A typica l remote control application uses an NEC protocol data-burst with a low impedance 3V supply and 1.6V drop (at 250mA) across the LED load. Under these conditions, the power dissipation related error in I_Out will be approximately 3% average during the burst.
Ordering Information
7”/13” Tape and Reel Quantity Part Number Suffix AP8804SNG-7 SN DFN2020-6 3000/ Tape & Reel -7 Marking Information A7 = Product Type Marking Code Y = Year 0 ~ 9 W = Week: A ~ Z : 1 ~ 26 Week; a ~ z : 27 ~ 52 week; z represents 52 and 53 week Y W X
Document number: DS32050 Rev. 2 - 5 8 of 9 www.diodes.com February 2010 © Diodes Incorporated CONFIDENTIAL A Product Line of Diodes Incorporated Package Outline Dimensions Suggested Pad Layout DFN2020-6 Dim Min Max Typ A 0.57 0.63 0.60 A1 0 0.05 0.03 A3 ⎯ ⎯ 0.15 b 0.20 0.30 0.25 D 1.95 2.075 2.00 D2 1.45 1.65 1.55 e ⎯ ⎯ 0.65 E 1.95 2.075 2.00 E2 0.76 0.96 0.86 L 0.30 0.40 0.35 All Dimensions in mm Dimensions Value (in mm) Z 1.67 G 0.15 X1 0.90 X2 0.45 Y 0.37 C 0.65 SEATING PLANE D e Pin#1 ID L b D2/2 E2E A A3 G G YC Z Y
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