AS3645 austriamicrosystems, AS3645 Datasheet
AS3645
Available stocks
Related parts for AS3645
AS3645 Summary of contents
Page 1
... Ultra Small High efficient single/dual LED Flash Driver with Safety Features 1 General Description The AS3645 is an inductive high efficient DCDC step up converter with two current sources. The DCDC step up converter operates at a fixed frequency of 2MHz and includes soft startup to allow easy integration into noise sensitive RF systems ...
Page 2
... I C mode: Digital input with pulldown to control strobe time for flash function parallel interface mode: Open drain output to identify single/dual flash LED Control pin for the operating mode of the AS3645 set to high (e.g. VIN) for I C mode 2. set to low (GND) for parallel interface mode with fixed output currents 3 ...
Page 3
... Junction Temperature Storage Temperature Range Humidity Body Temperature during Soldering 1. Depending on actual PCB layout and PCB used; for peak power dissipation during flashing see document 'AS3645 Thermal Measurements derating factor changes the total continuous power dissipation (P DERATE 70ºC. Therefore for e.g. T =85º ...
Page 4
... ISET 2 I >=320mA mode or parallel LED_OUT interface mode with fixed output currents Ramp-up During startup Ramp-down after AS3645 is disabled by interface I = 320mA LED_OUT Minimum voltage between pin VOUT and LED_OUT for operation of the current source Current used for single/dual LED detection V > ...
Page 5
... AS3645 Datasheet - Table 3. Electrical Characteristics (Continued) Symbol Parameter Maximum Current I RISETMAX through R ISET V Voltage on R ISET ISET Voltage on pin I2C/EN Maximum voltage on pin I2C/EN in shutdown if V TXMASK Protection and Fault Detection Functions ...
Page 6
... AS3645 Datasheet - Table 3. Electrical Characteristics (Continued) Symbol Parameter Pulldown current GND Resistor detection I RESDET_I2C current threshold TORCH debounce t DEBTORCH time t Pin I2C/EN timing I2C/ENDEB mode timings - see ...
Page 7
... AS3645 Datasheet - During every startup the logic level of the pin I2C/EN is checked logic low is detected, the pin I2C/EN is forced the resulting current is below I ISET parallel interface mode with adjustable output currents). ...
Page 8
... IOUT = 320mA/2 LEDs IOUT = 400mA/2 LEDs 50 2.7 3.1 3.5 3.9 4.3 Input Voltage (V) Figure 6. I Startup (two LEDs, I LED LED_OUT the AS3645 DCDC waits until it is in-regulation before rampup continues 250µs/Div Figure 8. I Startup (two LEDs, I LED LED_OUT 100µs/Div www.austriamicrosystems.com Figure 5. Application Efficiency ( ...
Page 9
... Ambient Temperature (C) www.austriamicrosystems.com Figure 11. I LED_OUT 500 400 300 200 100 0 0 0.5 Figure 13. I LED_OUT 324 only AS3645B 323 322 321 320 319 40 45 -40 -20 Ambient Temperature (C) Figure 15. Flash Timeout AMB 60 80 Revision 1.6 Linearity of current sink ILED = 200mA ILED = 300mA ...
Page 10
... AS3645 Datasheet - Detailed Description The AS3645 is a high performance DCDC step up converter with internal PMOS and NMOS switches. Its output is 1 connected to a flash LED with an internal current source. A separate current source is used to connect an indicator LED ...
Page 11
... AS3645 Datasheet - Protection and Fault Detection Functions The protection functions protect the AS3645 and the LED(s) against physical damage. In most cases a register bit is 2 set, which can be readout mode parallel interface mode the fault bits are cleared when the device enters shutdown mode. ...
Page 12
... Device Startup and Operating Mode selection AS3645A Operating Mode The AS3645A chooses the operating mode according to the digital input level on pin I2C/EN. If I2C/EN= selected, if I2C/EN=L parallel interface mode with fixed output currents is used. AS3645B Operating Mode Figure 17. AS3645B operating mode selection flow ...
Page 13
... AS3645 Datasheet - Figure 18. Single/Dual LED detection 2 The detection can be disabled mode by clearing the bit led_amount default value (‘1’ for dual LED) is used. This bit can be overwritten by software parallel interface mode, the pin STROBE is used as an open drain output to indicate if a single or a dual LED was detected: STROBE=L indicates single LED, STROBE=H (open drain) indicates dual LED detected ...
Page 14
... AS3645 Datasheet - Interface Mode: parallel interface mode with adjustable output currents - only AS3645B The output currents and operating mode in parallel interface mode with fixed output currents is selected according to 8 the following table : Table 5 ...
Page 15
... Datasheet - Interface Mode mode 2 The output currents and operating mode in parallel interface mode with fixed output currents are selected according to 9 the following table : 2 Table mode AS3645 configuration mode_ out_on setting (see (see page page 23) 23) 10, 01 ...
Page 16
... Figure 20. AS3645 flash duration defined by flash_timeout, starting flash with STROBE rising edge % & Figure 21. AS3645 flash duration and start defined by STROBE, limited by flash_timeout; timer not expired " & 10.flash mode is selected by setting www.austriamicrosystems.com flash_timeout and flash started immediately when this mode is selected by ...
Page 17
... The device that controls the message is called a master. The devices that are controlled by the master are referred to as slaves. A master device that generates the serial clock (SCL_EN1), controls the bus access, and generates the START and STOP conditions must control the bus. The AS3645 operates slave on the I C bus ...
Page 18
... Slave Transmitter Mode (Read Mode): The first byte is received and handled as in the slave receiver mode. However, in this mode, the direction bit indicates that the transfer direction is reversed. Serial data is transmit- ted on SDA_EN2 by the AS3645 while the serial clock is input on SCL_EN1. START and STOP conditions are recognized as the beginning and end of a serial transfer the first byte received after the master generates a START condition ...
Page 19
... Datasheet - register pointer is not written to before the initiation of a read mode the first address that is read is the last one stored in the register pointer. The AS3645 must receive a “not acknowledge” to end a read. Figure 24. Data Write - Slave Receiver Mode < ...
Page 20
... This is a fixed identification (e.g. to verify the I 11h R Version Control This register defines design versions Default Access Xh R AS3645 version number Xh R Indicator/Flash Timer This register defines Indicator Current and Flash Timeouts Default Access Define the duration of the flash timeout timer 0h 1h ...
Page 21
... AS3645 Datasheet - Table 9. Indicator/Flash TimerRegister (Continued) Addr: 2 Bit Bit Name ind_current 7:6 Table 10. Current Set Register Addr: 3 Bit Bit Name assist_light_current 2:0 3 led_det_on www.austriamicrosystems.com Indicator/Flash Timer This register defines Indicator Current and Flash Timeouts ...
Page 22
... AS3645 Datasheet - Table 10. Current Set Register (Continued) Addr: 3 Bit Bit Name flash_current 7 parallel interface mode the assist and torch current is set to 80mA for a single LED and 40mA for a dual LED 2. In parallel interface mode the flash current is set to 500mA for one LED and 320mA (each LED) for two LEDs 3 ...
Page 23
... Register Addr: 5 Bit Bit Name reserved 0 fault_coil_peak 1 www.austriamicrosystems.com Control This register defines the operating mode and different protection functions in I Default Access Define the AS3645 operating mode (only used see also 00 R Enables the STROBE input 0 1 R/W 1 Enables the output current sources (pin LED_OUT and ...
Page 24
... AS3645 Datasheet - Table 12. Fault Register (Continued) Addr: 5 Bit Bit Name fault_ind_led 2 3 led_amount fault_timeout 4 fault_overtemp 5 fault_led_short 6 fault_ovp 7 Table 13. Boost Register Addr: Dh Bit Bit Name 1 0 boost_current 1. Write 55h to register 0Fh (Password) before changing this register bit; when setting boost_current=1 also set led_det_on=0, led_amount=0 to disable led amount detection ...
Page 25
... AS3645 Datasheet - Register Map (I C mode) 2 Table 15. Register Map Register Addr Default Definition Name Design Info 0 11h Version Control 1 XXh Indicator/Flash 2 0Fh Timer Current Set 3 69h Control 4 B4h Fault 5 08h Boost Dh 00h ...
Page 26
... AS3645 Datasheet - Application Information The AS3645 supports different interface types possible to connect the AS3645 directly to an (existing (e.g. from the baseband processor) 2 Figure 27. Application Circuit using I C mode of BaseBand As the TORCH pin has an internal debounce timer and pulldown it is possible to connect TORCH directly to a push button (The control signal on the pins SCL/EN1 and SDA_EN2 always have higher priority compared to TORCH) ...
Page 27
... TXMask-ing of battery current - only AS3645B If the battery has to supply two high current loads at the same time (e.g. the AS3645 flash and a RF-power amplifier possible, that the total current causes a high voltage drop on the battery and with a low battery resulting in a shut- down of the complete system. In order to avoid this shutdown, the AS3645 can reduce its current with the signal ‘ ...
Page 28
... If a different output capacitor is chosen, ensure similar ESR values and at least 4µF capacitance at 10V output voltage. Inductor L DCDC The fast switching frequency (2MHz) of the AS3645 allows for the use of small SMDs for the external inductor. The saturation current I should be chosen to be above the maximum value of I ...
Page 29
... Therefore it is possible to selftest the application during assembly and manufacturing of the end-device. Depending on the operating mode following procedures are possible (for all tests the AS3645 should be started first by enabling e.g. torch mode to test the flash LED and the DCDC converter and enabling indicator mode to test the indica- tor LED): Table 19 ...
Page 30
... Inductor shorted Output or input capacitor excessive current from the supply - if a battery is connected it will trigger its shorted Enable AS3645 Indicator Mode and wait at least 1ms to detect following faults register bit Indicator LED shorted Indicator LED open register bit 1. Only possible if the test equipment has access to the STROBE pin 2 ...
Page 31
... Line 1: austriamicrosystems logo Line 2: AS3645 for AS3645A AS364B for AS3645B Line 3: <Code> Encoded Datecode (4 characters) Figure 32. 12pin WL-CSP 2x1.6mm Package Dimensions ! #$ % &$' % % % ) ) ) * * * The coplanarity of the balls is 40µm. www.austriamicrosystems.com (see AS3645A Operating Mode on page 12) (see AS3645B Operating Mode on page 12) % % ) ) * * Revision 1.6 ( % ) * ...
Page 32
... Table 20. Delivery Form detection Tape & Reel ISET detection Tape & Reel ISET detection function (see AS3645A Operating Mode on page 12) detection function (see AS3645B Operating Mode on page 12) Revision 1.6 Package 12-pin WL-CSP (2mm x 1.6mm) RoHS compliant / Pb-Free 12-pin WL-CSP (2mm x 1.6mm) RoHS compliant / Pb-Free ...
Page 33
... AS3645 Datasheet - Copyrights Copyright © 1997-2010, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, trans- lated, stored, or used without the prior written consent of the copyright owner. ...