rt8297a Richtek Technology Corporation, rt8297a Datasheet
rt8297a
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rt8297a Summary of contents
Page 1
... The RT8297A high efficiency, monolithic synchronous step-down DC/DC converter that can operate at 340kHz/800kHz, while delivering up to 1.5A output current from 17V input supply. The RT8297A/B's current mode architecture allows the transient response to be optimized. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up ...
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... RT8297A/B Typical Application Circuit 17V PGOOD Chip Enable (Exposed Pad 17V PGOOD Chip Enable (Exposed Pad) RT8297A RT8297B www.richtek.com 2 RT8297A 2 VIN BOOT C IN 10µ PGOOD GND RT8297B 2 VIN BOOT C IN 10µ PGOOD ...
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... Bootstrap for High Side Gate Driver. Connect 0.01μF or greater ceramic capacitor from BOOT to SW pin. Chip Enable. A logic-high enables the converter; a logic-low forces the RT8297A/B into shutdown mode, reducing the supply current to less than 5μA. Attach this pin to VIN with a 100kΩ pull up resistor for automatic startup. ...
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... 0. DS(ON)1 R DS(ON)2 Min. Duty Cycle, V BOOT Maximum Loading = 1.5A From Drain to Source For RT8297A f OSC1 For RT8297B V = 0V, For RT8297A FB f OSC2 V = 0V, For RT8297B 0.7V, For RT8297A FB D MAX V = 0.7V, For RT8297B FB Min Typ -- 1 -- 0.6 0.788 0 145 -- 140 − 300 ...
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... Note 4. The device is not guaranteed to function outside its operating conditions. DS8297A/B-00 March 2011 Symbol Test Conditions UVLO ΔV UVLO IH VIL Δ 25° high effective thermal conductivity four-layer test board of A RT8297A/B Min Typ Max Unit -- 100 -- 320 -- mV 2 0.4 μA ...
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... Load Current (A) Output Voltage vs. Output Current 5.10 5.06 5.02 4.98 4.94 RT8297A, V 4.90 0.0 0.3 0.6 Output Current (A) Reference Voltage vs. Temperature 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 RT8297A, V 0.60 -50 - Temperature (°C) www.richtek.com 3.3V = 1.2V RT8297A 12V IN 1.00 10.00 = 12V OUT 0.9 1.2 1.5 = 12V OUT 50 75 100 125 Efficiency vs. Load Current 100 OUT V = 3.3V 60 OUT V = 1.2V OUT 50 40 ...
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... Input Voltage (V) Frequency vs. Temperature 400 375 350 325 300 275 RT8297A, V 250 -50 - Temperature (°C) Quiescent Current vs. Input Voltage 900 850 800 750 700 650 RT8297A, V 600 Input Voltage (V) DS8297A/B-00 March 2011 = 3.3V 0.3A OUT OUT 3.3V 0.3A OUT OUT 50 75 ...
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... RT8297A/B Quiescent Current vs. Temperature 0.90 0.85 0.80 0.75 0.70 0.65 RT8297A 12V 0.60 -50 - Temperature (°C) Current Limit vs. Input Voltage 3.8 RT8297A 3.6 3.4 V OUT 3.2 3.0 V OUT 2.8 2.6 2.4 2.2 2 Input Voltage (V) Current Limit vs. Input Voltage 4.0 RT8297B V = 3.3V 3.8 OUT 3 1.2V 3.4 OUT 3.2 3.0 2.8 2.6 2.4 2.2 2 Input Voltage (V) www.richtek.com 8 = 3.3V 0.85V 100 125 = 3. ...
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... OUT (1A/Div 12V 3.3V OUT Time (1ms/Div) Switching RT8297B OUT I L (1A/Div 12V Time (500ns/Div) Power Off from (5V/Div) PGOOD (5V/Div) V OUT (2V/Div) I OUT (2A/Div 12V Time (100μs/Div) = 0.1A to 1.5A OUT = 3.3V 1.5A OUT OUT RT8297A = 3.3V 1.5A OUT OUT www.richtek.com 9 ...
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... RT8297A/B Power On from EN RT8297B 12V (5V/Div) PGOOD (5V/Div) V OUT (2V/Div) I OUT (2A/Div) Time (500μs/Div) www.richtek.com 10 = 3.3V 1.5A OUT OUT Power Off from EN RT8297B 12V OUT V EN (5V/Div) PGOOD (5V/Div) V OUT (2V/Div) I OUT (2A/Div) Time (100μs/Div) DS8297A/B-00 March 2011 = 3 ...
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... The bootstrap diode can be a low cost one such as 1N4148 or BAT54. The external 5V can fixed input from system output of the RT8297A/B. Note that the external boot voltage must be lower than 5.5V BOOT ...
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... P D(MAX) where the ambient temperature, and thermal resistance. For recommended operating condition specifications of the RT8297A/B, the maximum junction temperature is 125°C and ambient thermal resistance, immediately shifts by an amount OUT (ESR) also begins to charge or discharge LOAD generating a feedback error signal for the regulator to its steady-state value ...
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... Ambient Temperature (°C) Figure 3. Derating Curve for the RT8297A/B Package DS8297A/B-00 March 2011 θ Layout Consideration JA Follow the PCB layout guidelines for optimal performance T = 25°C of the RT8297A/B A Keep the traces of the main current paths as short and wide as possible. Put the input capacitor as close as possible to the device pins (VIN and GND) ...
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... RT8297A/B 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 Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time ...