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AN_SY8088 

  

AN_SY8088 Rev. 0.1                   Silergy Corp. Confidential- Prepared for Customer Use Only                   4 

Typical Performance Characteristics 

Efficiency vs. Load Current

Load Current (mA)

1

10

100

1000

65

70

75

80

85

90

95

V

IN

=5.0V,V

OUT

=1.2V

V

IN

=3.3V,V

OUT

=1.2V

V

IN

=4.2V,V

OUT

=1.2V

                    

Efficiency vs. Load Current

Load Current (mA)

1

10

100

1000

70

75

80

85

90

95

V

IN

=4.2V,V

OUT

=1.8V

V

IN

=3.3V,V

OUT

=1.8V

V

IN

=5.0V,V

OUT

=1.8V

 

Efficiency vs. Load Current

Load Current (mA)

1

10

100

1000

70

75

80

85

90

95

100

V

IN

=5V,V

OUT

=3.3V

V

IN

=4.2V,V

OUT

=3.3V

                           

Output Ripple

∆Vout  

20mV/div

L

X

2.0V/div

(V

IN

=5.0V, V

OUT

=1.8V, I

LOAD

=0A)

Time (400ns/div)

I

L

0.5A/div

 

Output Ripple

∆Vout  

20mV/div

L

X

2.0V/div

(V

IN

=5.0V, V

OUT

=1.8V, I

LOAD

=0.2A)

Time (400ns/div)

I

L

0.5A/div

                            

Output Ripple

∆Vout  

20mV/div

L

X

2.0V/div

(V

IN

=5.0V, V

OUT

=1.8V, I

LOAD

=1A)

Time (400ns/div)

I

L

1.0A/div

 

Summary of Contents for SY8088

Page 1: ...088 Package Code Temperature Code Optional Spec Code SY8088 Temperature Range 40 C to 85 C Features Low RDS ON for internal switches top bottom 260mΩ 170mΩ 2 5 5 5V input voltage range 40µA typical quiescent current High light load efficiency High switching frequency 1 5MHz minimizes the external components Internal soft start limits the inrush current 100 dropout operation RoHS Compliant and Halo...

Page 2: ... Feedback Pin Connect this pin to the center point of the output resistor divider as shown in Figure 1 to program the output voltage VOUT 0 6 1 R1 R2 Add optional C1 10pF 47pF to speed up the transient response Absolute Maximum Ratings Note 1 Supply Input Voltage 6 0V Enable FB Voltage VIN 0 6V Power Dissipation PD TA 25 C SOT23 5 0 6W Package Thermal Resistance Note 2 θJA 170 C W θJC 130 C W Junc...

Page 3: ...ime 80 ns Max Duty Cycle 100 Soft Start Time TSS 1 ms Thermal Shutdown Temperature TSD 160 C Thermal Shutdown Hysteresis THYS 15 C Note 1 Stresses beyond the Absolute Maximum Ratings may cause permanent damage to the device These are for stress ratings Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not...

Page 4: ...nt mA 1 10 100 1000 70 75 80 85 90 95 VIN 4 2V VOUT 1 8V VIN 3 3V VOUT 1 8V VIN 5 0V VOUT 1 8V Efficiency vs Load Current Load Current mA 1 10 100 1000 70 75 80 85 90 95 100 VIN 5V VOUT 3 3V VIN 4 2V VOUT 3 3V Output Ripple Vout 20mV div LX 2 0V div VIN 5 0V VOUT 1 8V ILOAD 0A Time 400ns div IL 0 5A div Output Ripple Vout 20mV div LX 2 0V div VIN 5 0V VOUT 1 8V ILOAD 0 2A Time 400ns div IL 0 5A di...

Page 5: ...pared for Customer Use Only 5 Time 400µs div Startup from Enable VIN 5 0V VOUT 1 8V ILOAD 1 0A LX 5 0V div VOUT 1 0V div EN 5 0V div IL 1 0A div Time 40µs div Shutdown from Enable VIN 5 0V VOUT 1 8V ILOAD 1 0A LX 5 0V div VOUT 1 0V div EN 5 0V div IL 1 0A div ...

Page 6: ...tance is calculated as OUT OUT IN MAX SW OUT MAX 40 V 1 V V L F I where Fsw is the switching frequency and Iout max is the maximum load current The SY8088 regulator IC is quite tolerant of different ripple current amplitude Consequently the final choice of inductance can be slightly off the calculation value without significantly impacting the performance 2 The saturation current rating of the ind...

Page 7: ...he LX net on the PCB layout to avoid the noise problem 5 If the system chip interfacing with the EN pin has a high impedance state at shutdown mode and the IN pin is connected directly to a power source such as a LiIon battery it is desirable to add a pull down 1Mohm resistor between the EN and GND pins to prevent the noise from falsely turning on the regulator at shutdown mode ...

Page 8: ... 95 TYP 2 40 0 80 0 55 0 95 TYP 1 50 1 70 0 30 0 50 2 80 3 10 2 70 3 00 1 50 1 70 0 30 0 50 2 80 3 10 2 70 3 00 Recommended Pad Layout 0 1 0 15 0 25 REF 0 3 0 6 0 1 0 15 0 25 REF 0 3 0 6 1 0 1 3 0 01 0 1 1 90 TYP 0 95 TYP 1 0 1 3 0 01 0 1 1 90 TYP 0 95 TYP Notes All dimensions are in millimeters All dimensions don t include mold flash metal burr ...

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