MIC2536-1BM Micrel Inc, MIC2536-1BM Datasheet - Page 10

• Manufacturer Part Number: MIC2536-1BM
• Description: IC USB SWITCH DUAL 8-SOIC
• Manufacturer: Micrel Inc
• Type: USB Switchr

Specifications of MIC2536-1BM

• Number Of Outputs: 2
• Rds (on): 700 mOhm
• Internal Switch(s): Yes
• Current Limit: 275mA
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

MIC2536
Applications Information
Supply Filtering
A 0.1 F to 1 F bypass capacitor from IN to GND, located at
the device, is strongly recommended to control supply tran-
sients. Without a bypass capacitor, an output short may
cause sufficient ringing on the input (from supply lead induc-
tance) to damage internal control circuitry.
Input or output transients must not exceed the absolute
maximum supply voltage (V
duration.
MIC2536
Figure 1. Supply Bypassing
ENA
FLGA
FLGB
ENB
MIC2536
OUTA
OUTB
GND
IN
2.7V to 5.5V
to "Hot"
Receptacle
IN(max)
V
IN
0.1µF to 1µF
GND
V
CC
= 6V) even for a short
Figure 2. Hot-Plug Card Application
Logic Controller
OVERCURRENT
Figure 3. Transient Filter
0.1
µF
1
2
3
4
10
C
Adaptor Card
10k
R
EN
FLGA
FLGB
ENB
MIC2536-2
Enable Input
EN must be driven logic high or logic low for a clearly defined
input. Floating the input may cause unpredictable operation.
EN should not be allowed to go negative with respect to GND.
Printed Circuit Board Hot-Plug
The MIC2536 is an ideal inrush current-limiter for hot-plug
applications. Due to the integrated charge pump, the MIC2536
presents a high impedance when off and slowly becomes a
low impedance as it turns on. This “soft-start” feature effec-
tively isolates power supplies from highly capacitive loads by
reducing inrush current. Figure 2 shows how the MIC2536
may be used in a hot-plug card application.
Overcurrent Transients
The MIC2536 incorporates an internal circuit designed to
prevent FLG from being asserted due to transient inrush
current. Overcurrent events <12ms (typ.) will not assert FLG.
In case of large capacitive loads (i.e., >430 F), the length of
the transient due to inrush current may exceed the delay
provided by the integrated filter. Since this inrush current
exceeds the current-limit delay specification, FLG will be
asserted during this time. To prevent the logic controller from
responding to FLG being asserted, an external RC filter, as
shown in Figure 3, can be used to filter out transient FLG
assertion. The value of the RC time constant should be
selected to match the length of the transient, minus flag t
V+
1
2
3
4
OUTA
OUTB
GND
EN
FLGA
FLGB
ENB
IN
MIC2536
8
5
7
6
OUTA
OUTB
GND
IN
8
5
C
7
6
BULK
Backend
Function
March 2000
Micrel
D
.