XC9290/91
THE WORLDS SMALLEST 600mA BUCK DC/DC CONVERTER
XC9290/91 6.0V 600mA Step-Down Sychronous DC/DC Converter with HiSAT-COT control
The XC9290/91 is an ultra-small synchronous step-down DC/DC which can operate from 2.5V to 6.0V and deliver loads up to 600mA. HiSAT-COT control ensures ultra-fast load transient response performance whilst maintaining a stable switching frequency. Two versions are available, with switching frequencies of either 4.0MHz or 6.0MHz.
| Series | XC9290 |
XC9291 |
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| Output Current | 600mA | ||||
| ON Resistance |
P-Ch | 0.26Ω (typ) | |||
| N-Ch | 0.32Ω (typ) | ||||
| Input Voltage Range | 2.5V ~ 6.0V | ||||
| Output Voltage Range | 0.7V ~ 3.6V | ||||
| Switching Frequency | 4.0MHz or 6.0MHz | ||||
| Quiescent Current (typ.) | 700μA | 11μA | |||
| PWM | PWM/PFM | ||||
| Max Duty Cycle | 100% | ||||
| Protection Circuits | Current Limit UVLO |
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| Additional Features | Soft-start | ||||
| Optional CL Discharge | |||||
| Package | LGA-6B01 or WLP-5-08 | ||||
TYPICAL APPLICATION CIRCUIT
EFFICIENCY vs. OUTPUT CURRENT
LOW OUTPUT RIPPLE
STABLE SWITCHING FREQUENCY
LOAD TRANSIENT RESPONSE
Utilising HiSAT-COT, Torex’s Constant ON Time architecture ensures extremely fast load transient response performance when compared with standard DC/DC solutions.
HiSAT-COT also provides less fluctuation in oscillation frequency against load and input voltage when compared to traditional COT control architectures.
IOUT = 1mA ⇔ 300mA (tr, tf = 5μs)
L = 0.47μH(LSCNB1005EETR47MB)
CIN = 4.7μF(GRM035R60J475ME15)
CL = 4.7μF(C1005X5R0J475K)
LOW ELECTROMAGNETIC INTERFERENCE (EMI)
The PCB area and subsequently the length of copper tracks is minimised due to the use of ultra-small packaging and smaller external components.
This results in extremely low radiated noise and excellent EMI performance as illustrated in the graph.
The XC9290/91 passes EN55032 (CISPR 32) CLASS B with good margin.
The graph shows our XC9291x18E with VIN=3.7V, VOUT=1.8V, fOSC=6MHz
ANY OUTPUT CAPACITOR
As shown in the graph, the CL capacitance value will reduce to 2μF at 1.8V and this will further decrease at higher temperatures.
The XC9290/91 is designed to operate with lower capacitance values which will occur under DC bias conditions.
As a result, designers can safely use smaller, lower cost, 0603 sized (0.6 x 0.3 x 0.5mm) multilayer capacitors without sacrificing performance.
