Richtek RT9706 User Manual
Evaluation Board
RT9706
80m
ΩΩ
Ω, 500mA High-Side Power Switch with Flag
ΩΩ
General Description
The RT9706 is a cost-effective, low voltage, single
N-Channel MOSFET high-side power switch, optimized
for self-powered and bus-powered Universal Serial Bus
(USB) application s. The RT9706 equipped with a charge
pump circuitry to drive the internal MOSFET switch; the
switch's low R
requirements; and a flag output is available to indicate
fault conditions to the local USB controller.
Additional features include soft-start to limit inrush current
during plug-in, thermal shutdown to prevent catastrophic
switch failure from high-current loads, under-voltage
lockout (UVLO) to ensure that the device remains off
unless there is a valid input voltage present, lower
quiescent current as 25μA making this device ideal for
portable battery operated equipment.
IC Part Number
Board Number
, 80mΩ, meets USB voltage drop
DS(ON)
RT9706
RT9706 SOT-23-5_V0
Features
zz
z
Compliant to USB Specifications
zz
zz
z
Built-In (Typically 80m
zz
zz
z
Output Can Be Forced Higher than Input (Off-State)
zz
zz
z
Guaranteed 500mA Continuous Load Current
zz
zz
z
Wide Input Voltage Ranges : 2V to 5.5V
zz
zz
z
Open-Drain Fault Flag Output
zz
zz
z
Hot Plug-In Application (Soft-Start)
zz
zz
z
1.7V T ypical Under-Voltage Lockout (UVLO)
zz
zz
z Current Limiting Protection
zz
zz
z Thermal Shutdown Protection
zz
zz
z Reverse Current Flow Blocking (no body diode)
zz
zz
z UL Approved
zz
−−
−E219878
−−
ΩΩ
Ω) N-Channel MOSFET
ΩΩ
Applications
z USB Bus/Self Powered Hubs
z USB Peripherals
z ACPI Power Distribution
z PC Card Hot Swap
z Notebook, Motherboard PCs
z Battery-Powered Equipment
z Hot-Plug Power Supplies
z Battery-Charger Circuits
Evaluation Board
RT9706 SOT-23-5_V0
EVB9706-02 October 2007 www.richtek.com
V
EN
(5V/Div)
FLAG
(5V/Div)
I
OUT
(500mA/Div)
Flag Response
Time (10ms/Div)
R
= 0Ω
L
1
RT9706
Evaluation Board
Specification
Parameter Symbol Min Typ Max Units
Operation Voltage Range VIN 2 5 5.5 V
Under-voltage Lockout V
Under-voltage Hysteresis ΔV
1.3 1.7 2.4 V
UVLO
-- 0.1 -- V
UVLO
Logic-Low Voltage VIL -- -- 0.8 V
EN Threshold
Logic-High Voltage V
Current Limit I
2.0 -- -- V
IH
0.5 -- 1.25 A
LIM
FLAG Delay Time tD 5 12 20 ms
Thermal Shutdown Protection TSD
Thermal Shutdown Hysteresis ΔTSD
-- 130 --
-- 20 --
°C
°C
Schematic
/FLG or EN
Z8
2
1
/FLG
1
2
3
EN
1
Z9
EN or /FLG
RT9711 / RT9706
SOT-23 -5
/FLG
GND
EN
U1
VOUT
VDD
Z15
1
2
R3 R4
23
Q1
VOUTVOUT
Z12
1
Vout
VOUT
1
2
R5
Z10
GATE
1
C2
GATE
1
Z11
1
5
4
12
Cout
1
GND
VIN
1
2
VIN
VIN
Z6
VIN
Z5
1
1
3
2
1
Z14
Cin
1 2
3
2
1
Z13
C1
R1
R2
GND
Z7
1
2
Figure 1. EVB Circuit
EVB9706-02 October 2007www.richtek.com
Loading...