RT4723 RICHTEK | Alldatasheet
Document overview
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Technical content
Features
2.5V to 4.6V Supply Voltage Range Single Wire Protocol Fixed 4.6V Positive Voltage Output Negative Voltage Output from 0.6V to 2.4V per 0.1V by SWIRE Pin Auto-Mode Transition of 0.33x/0.5x Charge Pump Built-in Soft-Start 30mA Maximum Output Current Programmable Output Fast Discharge Function High Impedance Output when IC Shutdown UVLO, OCP , SCP, OTP Protection Shutdown Current < 1A Available in 15-Ball WL-CSP Package
Applications
AMOLED Bias in Portable Device Marking Information 36 : Product Code W : Date Code36W Simplified Application Circuit BOOST PGND VIN LXP SWIRE VOP VON C1P RT4723 GND CIN VIN CBOOST VOP COP VON CON C1N CF1 C2P C2N CF2
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4723-00 April 2016 Pin Configurations (TOP VIEW) VIN PGND C1N C1P VOP LXP VON GND BOOST GND C2N C2PSWIRE PGND GND C1 C2 C3 D3D1 E1 E2 E3 A1 A2 A3 B3B1 B2 WL-CSP-15B 1.39x2.07 (BSC) Functional Pin Description Pin No. Pin Name Pin Function A1, C2, D2 GND Ground. A2 VON Negative Terminal Output. A3 C2N Flying Capacitor 2 Negative Connection. B1 SWIRE Enable and VON Voltage Setting. B2, E1 PGND Power Ground. B3 C2P Flying Capacitor 2 Positive Connection. C1 VIN Power Input. C3 C1N Flying Capacitor 1 Negative Connection. D1 LXP Switching Node of Boost Converter. D3 C1P Flying Capacitor 1 Positive Connection. E2 BOOST Output Voltage of Boost Converter. E3 VOP Positive Terminal Output.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4723-00 April 2016 www.richtek.com Function Block Diagram SCP1 RP2 RP1 VOP C1N VIN GND PGND LXP PWM Logic UVLO OCP1 RN2 RN1 SCP2 VON DAC+ Oscillator Pulse Counter VREF Bandgap Reference -0.33x/-0.5x Charge Pump C1P Soft-Start LDO GM VREF DAC SWIRE VREF Fast Discharge VOP VON BOOST C2P C2N Operation The RT4723 is a highly integrated Boost , LDO and inverting charge pump to generate positive and negative output voltage. It can support input voltage range from 2.5V to 4.6V and the output current up to 30mA. The VOP positive output voltage is set at a typical value of 4.6V. The VON negative output voltage is set at a typical value of -2.4V and can be programmed through single wire protocol (SWIRE pin). The available voltage range is from -0.6V to -2.4V with 100mV per step. The RT 4723 provides Over- Temperature Protection (OTP) and Short Circuit Protection (SCP) mechanisms to prevent the device from damage with abnormal operations. When the SWIRE voltage is logic low for more than 350us, the IC will be shut down with low input supply current less than 1A.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4723-00 April 2016 Absolute Maximum Ratings (Note 1) Power Dissipation, PD @ TA = 25°C Package Thermal Resistance (Note 2) ESD Susceptibility (Note 3) Recommended Operating Conditions (Note 4)
Electrical Characteristics
unless otherwise specified.) Parameter Symbol Test Conditions Min Typ Max Unit Power Supply Input Voltage Range VIN 2.5 -- 4.6 V Under Voltage Lockout Threshold Voltage VUVLO_H VIN Rising -- 2.2 2.5 V VUVLO_L VIN Falling -- 2.1 2.3 V Over-temperature Protection TOTP (Note 5) -- 140 -- C Over-temperature Protection Hysteresis TOTP_HYST (Note 5) -- 15 -- C Shutdown Current ISHDN SWIRE = 0V -- -- 1 A Efficiency Peak 1 Eff_1 IOP = ION = 1mA -- 58 -- % Efficiency Peak 2 Eff_2 IOP = ION = 5mA -- 75 -- % Efficiency Peak 3 Eff_3 IOP = ION = 15mA -- 83 -- % LDO Output Positive Output Voltage Range VOP -- 4.6 -- V
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4723-00 April 2016 www.richtek.com Parameter Symbol Test Conditions Min Typ Max Unit Positive Output Voltage Accuracy VOP_ACC 1 -- 1 % Positive Output Current Capability IOP_MAX -- -- 30 mA Positive Output Voltage Ripple VOP_RIPPLE IOP = 20mA (Note 5) -- 10 -- mV Line Regulation VOP_LINE VIN = 2.9 to 4.5V, IOP = 20mA -- 5 -- mV Load Regulation VOP_LOAD IOP = 0mA to 30mA (Note 5) -- 5 -- mV Fast Discharge Resistance RDISP -- 105 -- Short Circuit Protection VSCP1 -- < 80% VOP -- V Charge Pump Output Negative Output Voltage Range VON 2.4 -- 0.6 V Negative Output Voltage Setting Range VON_SET Per step -- 100 -- mV Negative Output Voltage Accuracy VON_ACC 1 -- 1 % Negative Output Current Capability ION_MAX -- -- 30 mA Negative Charge Pump Switching Frequency fOSC_N 0.8 1 1.2 MHz Negative Output Voltage Ripple VON_RIPPLE ION = 20mA (Note 5) -- 20 -- mV Line Regulation VON_LINE VIN = 2.9 to 4.5V, ION = 20mA -- 10 -- mV Load Regulation VON_LOAD ION = 0mA to 30mA (Note 5) -- 30 -- mV Fast Discharge Resistance RDISN -- 60 -- Short Circuit Protection VSCP2 -- > 80% VON -- V Logic Input (SWIRE) SWIRE Turn-off Detection Time Toff_dly 350 -- -- s SWIRE Signal Stop Indicate Time Tstop 350 -- -- s Twait after Data Twait_int 10 -- -- ms Rising Input High Threshold Voltage Level VIH 1.2 -- VIN V Falling Input Low Threshold Voltage Level VIL 0 -- 0.4 V SWIRE Pull Low Resistor RSWIRE -- 300 -- k Wake up Delay Twkp -- -- 1 s SWIRE Rising Time TR -- -- 200 ns SWIRE Falling Time TF -- -- 200 ns Clocked SWIRE High TON 2 10 40 s Clocked SWIRE Low TOFF 2 10 40 s
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4723-00 April 2016 Parameter Symbol Test Conditions Min Typ Max Unit SWIRE to VOP On Time TVOP_ON -- 1.6 -- ms Input Clocked SWIRE Frequency fSWIRE 25 -- 250 kHz Note 1. Stresses beyond those listed “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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Note 2. JA is measured at TA = 25C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. Note 3. Devices are ESD sensitive. Handling precaution recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. Spec. is guaranteed by design.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. Table 1. Component List of Evaluation Board
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. Table 2. VON Output Voltage with SWIRE Pulse Table 3. VOP/VON Shutdown Discharge Selection with SWIRE Pulse
21 Enable
is default disabled and outputs keep high impedance state when fault or power-off condition .
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4723-00 April 2016 www.richtek.com Typical Operating Characteristics Efficiency vs. Output Current Output Current (A) Efficiency (%) VOP = 4.6, VON = 2.4V VIN = 4.5V VIN = 3.7V VIN = 2.7V VOP vs. Output Current 4.580 4.585 4.590 4.595 4.600 4.605 4.610 4.615 4.620 Output Current (A) VOP (V) VOP = 4.6, VON = 2.4V VIN = 2.7V VIN = 3.7V VIN = 4.5V VON vs. Output Current -2.410 -2.405 -2.400 -2.395 -2.390 -2.385 -2.380 -2.375 -2.370 -2.365 -2.360 Output Current (A) VON (V) VOP = 4.6, VON = 2.4V VIN = 4.5V VIN = 3.7V VIN = 2.7V VOP vs. Input Voltage 4.590 4.591 4.592 4.593 4.594 4.595 4.596 4.597 4.598 4.599 4.600 Input Voltage (V) VOP (V) IOP = 0mA IOP = 10mA IOP = 30mA VOP = 4.6, VON = 2.4V VON vs. Input Voltage -2.41 -2.40 -2.39 -2.38 -2.37 -2.36 -2.35 2.5 3 3.5 4 4.5 Input Voltage (V) VON (V) VOP = 4.6, VON = 2.4V IOP = 10mA IOP = 0mA IOP = 30mA VIN = 3.7V, VOP = 4.6V, VON = 2.4V Power On Time (1ms/Div) SWIRE (4V/Div) VON (0.5V/Div) VOP (1V/Div) IVIN (0.1A/Div)
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4723-00 April 2016 Power Off with Discharge Time (5ms/Div) SWIRE (4V/Div) VON (0.5V/Div) VOP (1V/Div) IVIN (0.1A/Div) VIN = 3.7V, VOP = 4.6V, VON = 2.4V Power OFF without Discharge Time (10ms/Div) SWIRE (4V/Div) VON (0.5V/Div) VOP (1V/Div) IVIN (0.1A/Div) VIN = 3.7V, VOP = 4.6V, VON = 2.4V Power On with SWIRE is Low Time (10ms/Div) SWIRE (4V/Div) VIN (2V/Div) VBOOST (2V/Div) VIN = 3.7V, VOP = 0V, VON = 0V VIN = 3.7V, VOP = 4.6V, VON = -2.4V Power On with SWIRE is High Time (10ms/Div) SWIRE (4V/Div) VIN (2V/Div) VBOOST (2V/Div) VIN = 3.7V Power On with SWIRE from Low to High Time (10ms/Div) SWIRE (4V/Div) VIN (2V/Div) VBOOST (2V/Div)
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4723-00 April 2016 www.richtek.com
Application Information
The RT4723 is a highly integrated Boost, LDO and inverting charge pump to generate positive and negative output voltages for AMLOED bias. It can support input voltage range from 2. 5V to 4.6V and the output current up to 30mA. The V OP positive output voltage is generated from the LDO supplied from a synchronous Boost converter, and V OP is set at a typical value of 4.6V. The Boost converter output also drives an inverting charge pump controller to generate VON negative output voltage which is set at a typical value of 2.4V. The negative output voltage can be programmed through the dedicated pin which implements single wire protocol and t he available voltage range is from 0.6V to 2.4V with 100mV per step. Input Capacitor Selection Input ceramic capacitor with 4.7 F capacita nce is suggested for applications. For better voltage filtering, select ceramic capacitors with low ESR, X5R and X7R types are suitable because of their wider voltage and temperature ranges. Boost Inductor Selection The inductance depends on the maximum input current. As a general rule, the inductor ripple current range is 20% to 40% of the maximum input current. If 40% is selected as an example, the inductor ripple current can be calculated according to the following equations : OUT OUT(MAX) IN(MAX) IN L IN(MAX) VII = V I = 0.4 I where η is the efficiency of the V OP Boost converter, IIN(MAX) is the maximum input current, and IL is the inductor ripple current. The input peak current can then be obtained by adding the maximum input current with half of the inductor ripple current as shown in the following equation : IPEAK = 1.2 x IIN(MAX) Note that the saturated current of the inductor must be greater than IPEAK. The inductance can eventually be determined according to the following equation : IN OUT IN OUT OUT(MAX) OSC η V V VL
0.4 V I f
where f OSC is the switching frequency. For better system performance, a shielded inductor is preferred to avoid EMI problems. Boost Output Capacitor Selection The output ripple voltage is an important index for estimating IC performance. This portion consists of two parts. One is the product of ripple current with the ESR of the output capacitor, while the other part is formed by the charging and discharging process of the output capacitor. As shown in Figure 1, VOUT1 can be evaluated based on the ideal energy eq ualization. According to the definition of Q, the VOUT1 value can be calculated as the following equation : OUT OUT OUT1 SOC OUTOUT1 SOC OUT 1Q = I D = C Vf IDV = fC where fOSC is the switching frequency and D is the duty cycle. Finally, taking ESR into consideration, the overall output ripple voltage can be determined by the following equation : OUTOUT ESR OUT1 ESR OSC OUT IDV = V + V = V + fC where VESR = ICrms x RCESR The output capacitor, C OUT, should be selected accordingly.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. Figure 1. Output Ripple Voltage Without Contribution of than the specified threshold voltage. “VON Output Voltage with SWIRE Pulse”. normal operation after triggering the SWIRE pin. 15C, IC will automatically resume normal operation. difference between junction and ambient temperature. standard JEDEC 51 -7 four -layer thermal test board.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. temperature on the maximum power dissipation. Figure 2. Derating Curve of Maximum Power PCB layout guidelines should be strictly followed. to the ground plane of the PCB. near LXP or high-current traces. connections between these separate ground planes.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. Figure 3. PCB Layout Guide
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4723-00 April 2016 www.richtek.com Outline Dimension Symbol Dimensions In Millimeters Dimensions In Inches Min. Max. Min. Max. A 0.500 0.600 0.020 0.024 A1 0.170 0.230 0.007 0.009 b 0.240 0.300 0.009 0.012 D 2.020 2.120 0.080 0.083 D1 1.600 0.063 E 1.340 1.440 0.053 0.057 E1 0.800 0.031 e 0.400 0.016 WL-CSP-15B 1.39x2.07 (BSC) Richtek Technology Corporation 14F, No. 8, Tai Yuen 1st Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications witho ut notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should ver ify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent righ ts of Richtek or its subsidiaries.