ISL8002_13 Datasheet, PDF (1/24 Pages) Intersil Corporation – Compact Synchronous Buck Regulators

Compact Synchronous Buck Regulators
ISL8002, ISL8002A, ISL80019, ISL80019A
ISL8002, ISL8002A, ISL80019 and ISL80019A are highly
efficient, monolithic, synchronous step-down DC/DC converters
that can deliver up to 2A of continuous output current from a 2.7V
to 5.5V input supply. They use peak current mode control
architecture to allow very low duty cycle operation. They operate
at either 1MHz or 2MHz switching frequency, thereby providing
superior transient response and allowing for the use of small
inductors. They also have excellent stability and provide both
internal and external compensation options.
ISL8002, ISL8002A, ISL80019 and ISL80019A integrate very low
r_DS(ON) MOSFETs in order to maximize efficiency. In addition,
since the high side MOSFET is a PMOS, the need for a Boot
capacitor is eliminated, thereby reducing external component
count. They can operate at 100% duty cycle (at 1MHz) with a
dropout of 200mV at 2A output current.
These devices can be configured for either PFM (discontinuous
conduction) or PWM (continuous conduction) operation at light
load. PFM provides high efficiency by reducing switching losses at
light loads and PWM reduces noise susceptibility and RF
interference.
These devices are offered in a space saving 8 pin 2mmx2mm
TDFN lead free package with exposed pad for improved thermal
performance. The complete converter occupies less than
0.10in² area.
Features
• V_IN range 2.7V to 5.5V
• V_OUT range is 0.6V to V_IN
• I_OUT maximum is 1.5A or 2A (see Table 1 on page 3)
• Switching frequency is 1MHz or 2MHz (see Table 1 on
page 3)
• Internal or external compensation option
• Selectable PFM or PWM operation option
• Overcurrent and short circuit protection
• Over-temperature/thermal protection
• V_IN Undervoltage Lockout and V_OUT Overvoltage Protection
• Up to 95% peak efficiency
Applications
• General purpose point of load DC/DC
• Set-top boxes and cable modems
• FPGA power
• DVD, HDD drives, LCD panels, TV
Related Literature
• See AN1803, “1.5A/2A Low Quiescent Current High
Efficiency Synchronous Buck Regulator”
VIN
GND
+2.7V …+5.5V _{1 VIN}
C1
22μF
2 _EN
EN
3 _MODE
PG
4 _PG
ISL8002
PAD
9
L1
1.2μH
PHASE ⁸
C5
22μF
PGND ⁷
+1.8V/2A
C6
22μF
R1
FB ^{6 +0.6V 200kΩ 1%}
COMP ⁵
R2
100kΩ 1%
VOUT
GND
R₁
=
R₂
⎛
⎝
---^V----^O----
VFB
–
1_⎠⎞
FIGURE 1. TYPICAL APPLICATION CIRCUIT CONFIGURATION
(INTERNAL COMPENSATION OPTION)
(EQ. 1)
100
90
80
70
2.5V_OUT
60
1.8V_OUT
1.5V_OUT
50
1.2V_OUT
0.9V_OUT
0.8V_OUT
40
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
OUTPUT LOAD (A)
FIGURE 2. EFFICIENCY vs LOAD
F_SW = 1MHz, V_IN = 3.3V, MODE = PFM, T_A = +25°C
July 30, 2013
1
FN7888.2
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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