RT9209 RICHTEK [Richtek Technology Corporation], RT9209 Datasheet
RT9209
Available stocks
Related parts for RT9209
RT9209 Summary of contents
Page 1
... A fixed 260kHz/ 400kHz oscillator reduce the component size for saving board area. The RT9209/A future a enable control pin to shutdown PWM switching and a 90% power good flag indicator. The FB pin under voltage detection function monitor the output short circuit which trigger a three time hiccup sequence to latch off the chip function ...
Page 2
... BOOT 5 UGATE Figure A. RT9209/A Booted from 5V R2 250 R4 10K PGOOD 0.1uF 6 BOOT 5 UGATE RT9209 1uF Figure B. RT9209/A Booted from 12V C1 470uF MU C BOOT L1 A 5uH 0.1uF C4 ML 1000uF 5V PGOOD C1 470uF 5uH ML C4 1000uF DS9209/A-08 March 2007 ...
Page 3
... RT9209/A Layout Placement Layout Notes 1. Put C & near the MU drain and ML source nodes. IN1 IN2 2. Put RT9209 near the C 3. Put C as close as to BOOT pin BOOT 4. Put C as close as to VCC pin VCC Power on Reset Soft Start ...
Page 4
... This pin also connects to internal PWM error amplifier inverting input and protection monitor. VCC (Pin 2) This is the main bias supply for the RT9209/A. This pin also provides the gate bias charge for the lower MOSFETs gate. The voltage at this pin monitored for power-on reset (POR) purpose ...
Page 5
... I CC Δ V OSC BOOT= 12V R UGATE BOOT UGATE UGATE UGATE 1V, LGATE CC LGATE LGATE LGATE FB Rising FB Falling FB pin Rising I = 1mA PGOOD RT9209/A Min Typ Max Units -- 3.7 4.1 4.5 V 0.3 0.5 0.7 V 0.784 0.8 0.816 V 210 260 310 kHz 350 400 450 -- 1. P-P 33 ...
Page 6
... RT9209/A Typical Operating Characteristics Dead Time UGATE Time (50ns/Div) Dead Time UGATE Time (50ns/Div) Load Transient V OUT I OUT Time (10us/Div) www.richtek.com 6 Booted from 5V LGATE OUT Booted from 12V LGATE OUT UGATE 2.5V OUT C = 1000uF OUT I = 10A to 0A OUT ...
Page 7
... OUT Time (2.5ms/Div) Boostrap Waveform Booted from 5V Time (1us/Div) DS9209/A-08 March 2007 OUT OUT UGATE LGATE A node RT9209/A Power Off Booted from OUT Time (10ms/Div) Power Off Booted from 12V OUT Time (50ms/Div) Boostrap Waveform UGATE ...
Page 8
... 105 125 Short Hiccup Booted from 12V Time (25ms/Div) PGOOD vs. V PGOOD Time (25ms/Div) Oscillator Frequency vs. Temperature 410 400 390 380 370 360 350 -35 - Temperature DS9209/A-08 March 2007 UGATE V OUT OUT V OUT RT9209A 85 105 125 (°C) ...
Page 9
... POR(Rising/Falling) vs. Temperature 4.2 4.1 Rising 4 3.9 3.8 3.7 Falling 3.6 3.5 -35 - Temperature (°C) DS9209/A-08 March 2007 105 125 RT9209/A www.richtek.com 9 ...
Page 10
... LGATE RT9209/A Figure 1. Single 5V power Supply Operation Dual Power Operation The RT9209/A is designed to supply a regulated 6.5V at VCC pin automatically when BOOT pin is powered by a 12V system with ATX 5V/12V power supply, the RT9209/A is ideal for higher current applications due to the higher gate driving capability 6.5V (10Ω ...
Page 11
... COUNT = 2 COUNT = OVERLOAD APPLIED Figure 3 Inductor Selection The RT9209/A was designed for V application mainly. Figure 4 shows the typical topology and waveforms of step-down converter. The ripple currents of inductor can be calculated as follows: ( OUT × RIPPLE ON L Because operation frequency is fixed at 260kHz/400kHz, ...
Page 12
... LC filter pole Error Amp pole P = 300kHz A 1 π × × × ESR zero Z = ESR The RT9209/A Bode plot as shown Figure 5 is stable in most of application conditions 3.3V OUT C = 1500uF(33mΩ) OUT L = 2uH 2.9kHz OUT 2.5V OUT ...
Page 13
... PCB traces help in minimizing the magnitude of voltage spikes. There are two sets of critical components in a DC-DC converter using the RT9209/A. The switching power components are most critical because they switch large amounts of energy, and as such, they tend to generate equally large amounts of noise. The critical small signal components are those connected to sensitive nodes or those supplying critical bypass current ...
Page 14
... RT9209/A Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 www.richtek.com Dimensions In Millimeters Min Max 4.801 5.004 3.810 3.988 1.346 1.753 0.330 0.508 1.194 1 ...