CS51311GD14 Cherry Semiconductor Corporation, CS51311GD14 Datasheet
CS51311GD14
Related parts for CS51311GD14
CS51311GD14 Summary of contents
Page 1
... COMP pin Package Options 14 Lead SO Narrow VID0 COMP 1 VID1 C OFF VID2 PWRGD VID3 GATE(L) VID4 Gnd V GATE( OUT Cherry Semiconductor Corporation 2000 South County Trail, East Greenwich, RI 02818 Tel: (401)885-3600 Fax: (401)885-5786 Email: info@cherry-semi.com Web Site: www.cherry-semi.com A Company ® ...
Page 2
Operating Junction Temperature, T Lead Temperature Soldering Reflow (SMD styles only ...
Page 3
Electrical Characteristics: 0˚C < T 2.0V DAC Code ( ID4 ID3 ID2 PARAMETER Error Amplifier V Bias Current 0.2V ≤V FB COMP Source Current V COMP Sink Current V Open Loop Gain C Unity Gain Bandwidth C ...
Page 4
Electrical Characteristics: 0˚C < T 2.0V DAC Code ( ID4 ID3 ID2 PARAMETER Line Regulation Input Threshold Input Pull-up Resistance Pull-up Voltage GATE(H) and GATE(L) High Voltage at 100mA Low Voltage at 100mA Rise Time Fall Time ...
Page 5
Electrical Characteristics: 0˚C < T 2.0V DAC Code ( ID4 ID3 ID2 PARAMETER General Electrical Specifications V Monitor Start Threshold CC V Monitor Stop Threshold CC Hysteresis V Supply Current CC Note 1: The IC power dissipation ...
Page 6
Figure 1: Gate(H) and Gate(L) Falltime vs. Load Capacitance. 150 V = 12V 125 25°C A 100 2000 4000 6000 8000 10000 Load Capacitance (pF) Figure 2: Gate(H) and Gate(L) Risetime vs. ...
Page 7
The ramp signal also con- tains the DC portion of the output voltage, which allows the control circuit to drive the main ...
Page 8
COMP pin plus the 1.1V PWM comparator offset prior to the drop across the current sense resistor exceeding the current limit threshold. In this case, the PWM control loop has achieved regulation and ...
Page 9
When driving large capacitive loads, the COMP must charge slowly enough to avoid tripping the CS51311 over- current protection. The following equation can be used to ensure unconditional startup − I CHG LIM < COMP OUT ...
Page 10
This causes the regulator to stop switching. During this overcurrent condition, the CS51311 stays off for the time it takes the COMP pin capacitor to discharge to its lower 0.25V threshold. As soon as the COMP ...
Page 11
Number of capacitors = where ESR = maximum ESR per capacitor (specified in CAP manufacturer’s data sheet); ESR = maximum allowable ESR. MAX The actual output voltage deviation due to ESR can then be verified and compared to the value ...
Page 12
EMI. The inductor value can be determined by: (V − × OUT L = ∆Ι where V ...
Page 13
Once the total ESR of the input capacitors is known, the input capacitor ripple voltage can be determined using the formula CIN(RMS) CIN(RMS) where V = input capacitor RMS voltage; CIN(RMS total input RMS current; ...
Page 14
/dt). Unless the gate-drive DG GATE dg dg impedance is very low, the V waveform commonly GS plateaus during rapid changes in the drain-to-source volt- age. The most important aspect of FET performance is the ...
Page 15
Characteristics section switching frequency. SW The total power dissipation in the synchronous (lower) MOSFET can then be calculated as LFET(TOTAL) RMSL where P = Synchronous (lower) FET total losses; LFET(TOTAL Switch Conduction Losses; ...
Page 16
Therefore the error due to sheet resis- tivity is: 1.48 - 1.26 = ±8%. 1.37 2) Mismatch due to L/W The variation in L/W is governed by variations due to the PCB manufacturing process. The ...
Page 17
V TH(TYP CL(NOM) R SENSE(NOM) Maximum Current Limit Setpoint From the overcurrent detection data in the electrical char- acteristics table 101mV, TH(MAX) V TH(MAX CL(MAX SENSE(MIN) SENSE(NOM) 101mV = = ...
Page 18
The input filter inductor may not be required because bulk filter and bypass capacitors, as well as other loads located on the board will tend to reduce regulator di/dt effects on the circuit board and input power supply. Placement of ...
Page 19
... PACKAGE DIMENSIONS IN mm (INCHES) Lead Count Metric Max 14L SO Narrow 8.75 1.27 (.050) 0.40 (.016) REF: JEDEC MS-012 Ordering Information Part Number Description CS51311GD14 14L SO Narrow CS51311GDR14 14L SO Narrow (tape & reel) Rev. 3/11/99 Package Specification D Thermal Data English R Min Max Min ΘJC 8.55 .344 .337 R Θ ...