scholarly journals Negative Output Voltage Ripples of Bipolar DC–DC Converter LM27762 near Maximum Input Voltage

Author(s):  
V. K. Bityukov ◽  
N. G. Mikhnevich ◽  
V. A. Petrov

The paper presents the results of studies of the operation of the inverting DC–DC converter with charge pump and LDO, which are part of the combined bipolar secondary power supply LM27762, at the near to maximum input voltage of 5.5 V and an output voltage of –4.9 V. The ripple voltages were measured at various load currents from 10 to 250 mA at the positive pole of the flying capacitor, at the output of the charge pump system and at the output of the microcircuit. It was shown for the first time on the basis of the obtained information that at low load currents up to about 107 mA the charge pump system operates in the burst mode, and at currents greater than 109 mA – in the charge pump mode with a constant frequency. The results do not confirm the information in the documentation on the microcircuit that, at themaximum input voltage of 5.5 V, the charge pump can enter the PWM mode in hot conditions. When working in burst mode, the presence of LDO in the LM27762 chip reduces the ripples of the negative voltage at the output. However, they significantly exceed the values given in the documentation on the chip. During switching to the constant–frequency mode, the level of negative voltage ripples at the output of the microcircuit decreases sharply, but it increases with further increase of the load current and exceeds the values given in the documentation.

Author(s):  
V. K. Bityukov ◽  
A. V. Mironov ◽  
N. G. Mikhnevich ◽  
V. A. Petrov

The study tested output voltage pulsations and pulsations of voltage on a flying capacitor when MAX 1759 integrated circuit of DC-DC converter is pumped in a voltage boost mode with an output voltage of 3.6V and 5.2V at an input voltage of 3.2V and a load current in the range of 5...100 mA. The analysis of the results obtained shows that the hysteresis comparator is the basis for the charge pump control. The algorithm for operating the charge pump system is described for the first time in detail


Author(s):  
V. K. Bityukov ◽  
V. A. Petrov ◽  
A. A. Sotnikova

The paper focuses on the study of operation of an inverting DC-DC converter with charge pumping and LDO, which are the part of the combined bipolar secondary power supply LM 27762. The measurements covered two modes amply included in the range of normalized parameters with input voltages equal to 3.5 and 5.5 V, and output voltages 1.8 and 4.9 V, respectively, as well as the mode with an input voltage of 5.0 V and an output voltage 4.7 V, with a difference in the input and output voltage not exceeding the normalized limit of the voltage drop across LDO . Pulsations of voltages were measured at various load currents from 15 to 250 mA at the positive and negative poles of the flying capacitor, at the output of the charge pumping system and, in the latter case, also at the output of the microcircuit. Based on the results obtained, it was shown for the first time how at low load currents up to about 100 mA the charge pumping system operates in the burst mode, and at higher currents, it operates in the charge pumping mode with a constant frequency


2017 ◽  
Vol 26 (12) ◽  
pp. 1750196 ◽  
Author(s):  
Yanzhao Ma ◽  
Yinghui Zou ◽  
Shengbing Zhang ◽  
Xiaoya Fan

A fully-integrated self-startup circuit with ultra-low voltage for thermal energy harvesting is presented in this paper. The converter is composed of an enhanced swing LC oscillator and a charge pump with decreased equivalent input capacitance. The LC oscillator has ultra-low input voltage and high output voltage swing, and the charge pump has a fast charging speed and small equivalent input capacitance. This circuit is designed with 0.18[Formula: see text][Formula: see text]m standard CMOS process. The simulation results show that the output voltage is in the range of 0.14[Formula: see text]V and 2.97[Formula: see text]V when the input voltage is changed from 50[Formula: see text]mV to 150[Formula: see text]mV. The output voltage could reach 2.87[Formula: see text]V at the input voltage of 150[Formula: see text]mV and the load of 1[Formula: see text]M[Formula: see text]. The maximum efficiency is in the range of 10.0% and 14.8% when the input voltage is changed from 0.2[Formula: see text]V to 0.4[Formula: see text]V. The circuit is suitable for thermoelectric energy harvesting to start with ultra-low input voltage.


2019 ◽  
Vol 29 (01) ◽  
pp. 2050013
Author(s):  
Najmeh Cheraghi Shirazi ◽  
Abumoslem Jannesari ◽  
Pooya Torkzadeh

A new self-start-up switched-capacitor charge pump is proposed for low-power, low-voltage and battery-less implantable applications. To minimize output voltage ripple and improve transient response, interleaving regulation technique is applied to a multi-stage Cross-Coupled Charge Pump (CCCP) circuit. It splits the power flow in a time-sequenced manner. Three cases of study are designed and investigated with body-biasing technique by auxiliary transistors: Four-stage Two-Branch CCCP (TBCCCP), the two-cell four-stage Interleaved Two-Branch CCCP (ITBCCCP2) and four-cell four-stage Interleaved Two-Branch CCCP (ITBCCCP4). Multi-phase nonoverlap clock generator circuit with body-biasing technique is also proposed which can operate at voltages as low as CCCP circuits. The proposed circuits are designed with input voltage as low as 300 to 400[Formula: see text]mV and 20[Formula: see text]MHz clock frequency for 1[Formula: see text]pF load capacitance. Among the three designs, ITBCCCP4 has the lowest ramp-up time (41.6% faster), output voltage ripple (29% less) and power consumption (19% less). The Figure-Of-Merit (FOM) of ITBCCCP4 is the highest value among two others. For 400[Formula: see text]mV input voltage, ITBCCCP4 has a 98.3% pumping efficiency within 11.6[Formula: see text][Formula: see text]s, while having a maximum voltage ripple of 0.1% and a power consumption as low as 2.7[Formula: see text]nW. The FOM is 0.66 for this circuit. The designed circuits are implemented in 180-nm standard CMOS technology with an effective chip area of [Formula: see text][Formula: see text][Formula: see text]m for TBCCCP, [Formula: see text][Formula: see text][Formula: see text]m for ITBCCCP2 and [Formula: see text][Formula: see text][Formula: see text]m for ITBCCCP4.


Author(s):  
V. K. Bityukov ◽  
V. A. Petrov ◽  
A. A. Sotnikova

The paper presents investigation results concerning output ripple voltage and flying capacitor voltage in the integrated circuit of the MCP 1253 charge pump DC -to- DC converter operating in buck mode with various combinations of input and output voltage values (5.1 and 3.5 V, 5.1 and 4.8 V, 3.26 and 3.02 V, 2.59 and 2.18 V,2.52 and 1.71 V, 2.17 and 1.71 V) when load currents vary of 5…100 mA. The results obtained allowed us to show for the first time that operation algorithms of the charge pumping system in the MCP 1253 integrated circuit depend on the ratio of input to output voltage and variations in the load current.


2013 ◽  
Vol 3 (1) ◽  
pp. 349-351
Author(s):  
K. C. Selvam ◽  
S. Latha

A simple circuit which accepts a negative voltage as input and provides an output voltage equal to the square root of the input voltage is described in this paper. The square rooting operation is dependent only on the ratio of two resistors and a DC voltage. Hence, the required accuracy can be obtained by employing precision resistors and a stable reference voltage. The feasibility of the circuit is examined by testing the results on a proto type.


Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1623
Author(s):  
Bor-Ren Lin

In order to realize emission-free solutions and clean transportation alternatives, this paper presents a new DC converter with pulse frequency control for a battery charger in electric vehicles (EVs) or light electric vehicles (LEVs). The circuit configuration includes a resonant tank on the high-voltage side and two variable winding sets on the output side to achieve wide output voltage operation for a universal LEV battery charger. The input terminal of the presented converter is a from DC microgrid with voltage levels of 380, 760, or 1500 V for house, industry plant, or DC transportation vehicle demands, respectively. To reduce voltage stresses on active devices, a cascade circuit structure with less voltage rating on power semiconductors is used on the primary side. Two resonant capacitors were selected on the resonant tank, not only to achieve the two input voltage balance problem but also to realize the resonant operation to control load voltage. By using the variable switching frequency approach to regulate load voltage, active switches are turned on with soft switching operation to improve converter efficiency. In order to achieve wide output voltage capability for universal battery charger demands such as scooters, electric motorbikes, Li-ion e-trikes, golf carts, luxury golf cars, and quad applications, two variable winding sets were selected to have a wide voltage output (50~160 V). Finally, experiments with a 1 kW rated prototype were demonstrated to validate the performance and benefits of presented converter.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1212
Author(s):  
Kazuma Koketsu ◽  
Toru Tanzawa

This paper describes a charge pump system for a flexible thermoelectric generator (TEG). Even though the TEG has high-output impedance, the system controls the input voltage to keep it higher than the minimum operating voltage by modulating the input impedance of the charge pump using two-phase operation with low- and high-input impedance modes. The average input impedance can be matched with the output impedance of the TEG. How the system can be designed is also described in detail. A design demonstration was performed for the TEG with 400 Ω. The fabricated system was also measured with a flexible-type TEG based on carbon nanotubes. Even with an output impedance of 1.4 kΩ, the system converted thermal energy into electric power of 30 μW at 2.5 V to the following sensor ICs.


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