STCC2540
USB charging controller with integrated power switch
Datasheet - production data
Applications
• USB ports / hubs
• Personal computers, all-in-one PCs
• Monitors
• Notebooks, ultrabooks
• Tablet PCs
VFQFPN 16L 3 x 3 x 0.8 mm
• Universal wall charging adapters
Description
Features
• Compliant with USB charging specifications
BC1.2, USB 2.0 and USB 3.0 standards
• Compliant with Chinese telecommunications
industry standard YD/T 1591-2009
• Compatible with proprietary charging mode
(Apple® 1 A / 2 A, BlackBerry®, Korean tablets)
• Wide bandwidth, low-loss USB 2.0 data switch
• Integrated VBUS power switch with low RON of
65 mΩ
• Constant current mode overcurrent protection
• Soft-start to limit inrush current
• Adjustable current limit up to 2.8 A
• Short-circuit, thermal and undervoltage
protection
• Reverse voltage and reverse current protection
The STCC2540 device integrates, in one
package, a USB charger controller, a wide
bandwidth data switch, and a high current power
switch. The device emulates several profiles
compatible with the USB battery charging
standard, BC1.2, Chinese telecommunications
standard YD/T 1591-2009, and proprietary
charger modes.
The device asserts the charging flag in DCP
modes if the charging current is higher than the
threshold. In CDP mode, it asserts the charging
flag after the CDP negotiation if the charging
current is higher than the threshold.
After the current drops below the threshold, the
output is deasserted, allowing the host to turn off
the high power DC-DC converter and reduce
overall consumption in S4/S5 states, which is
critical when the host is battery supplied.
• Deglitched fault reporting output
• Supports remote wakeup in S3
• Charging indication output in DCP and CDP
modes
• Package: VFQFPN 16L 3 x 3 x 0.8 mm with
exposed pad
• Temperature range: -40 up to 85 °C
• UL and CB recognized components
(UL file number: E354278)
February 2014
This is information on a product in full production.
DocID024711 Rev 6
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www.st.com
Contents
STCC2540
Contents
1
Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3
Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 6
4
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1
Supported modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2
Remote wakeup in S3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.3
VBUS discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.4
State machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.5
Charging detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.6
Power switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Overcurrent conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Thermal protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Undervoltage lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
FAULT functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Current limit programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.7
Enable input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.8
Input and output capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6
Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
8
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2/32
DocID024711 Rev 6
STCC2540
1
Functional description
Functional description
The STCC2540 device integrates, in one package, a complete solution to charge portable
devices through USB ports, including:
•
Charger emulator compatible with USB battery charging BC1.2 standard, Chinese
telecommunications standard YD/T 1591-2009 and proprietary charger such as Apple®
divider mode, BlackBerry® and Korean tablet charging mode.
•
3 control pins, CTL1, CTL2, CTL3 allowing the host to select the emulation profile.
These pins may be controlled directly from the host USB controller or from the
embedded controller.
•
USB data switch with wide bandwidth up to 1100 MHz compliant with USB 2.0
standard. This wide bandwidth switch features low capacitance and low RON
resistance, allowing signals to pass with minimum edge and phase distortion.
•
N-channel power switch with low RON resistance of 65 mΩ typ., high current limiter
accuracy and high current output capability, 2.5 A typ. The current limit threshold can
be adjusted with a good accuracy by an external resistor in the range 500 mA to 2.8 A
(max.).
Constant current mode protection is used to protect the device and the host system
against overcurrent or short-circuit. Other protection includes reverse current and
reverse voltage protection, undervoltage lockout and thermal shutdown.
•
A deglitched output (FAULT) reporting the failure events of overcurrent, thermal
shutdown and reverse current (backdrive) to VIN.
•
Charging current sensing circuit. The output CHARGING is asserted if charging current
is above 20 mA in CDP and DCP modes.
In CDP mode the charging flag is s asserted only if the CDP handshaking between the
portable device and the host is performed before the current is above threshold.
After the current drops below threshold, the output CHARGING is deasserted. The host
system can then disable the high power DC-DC converter and thus reduce the power
consumption. This is crucial when the host is battery supplied.
•
An enable input (EN) to enable/disable the device.
The device is offered in a small, RoHS compliant VFQFPN 16L (3 x 3 x 0.8 mm) package
with an exposed pad for effective cooling.
DocID024711 Rev 6
3/32
32
Functional description
STCC2540
Figure 1. Block diagram
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DocID024711 Rev 6
STCC2540
2
Pin description
Pin description
Table 1. Pin description
Pin no.
Name
Type
Description
1
IN
2, 3
DM_OUT, DP_OUT
I/O
4
NC
-
Not connected
5
EN
I
Logic level control input. When EN is low, power switch, data switch and
emulator are OFF.
6, 7, 8
CTL1, CTL2, CTL3
I
Logic level control inputs to select charger mode (see Table 5).
9
CHARGING
O
Active low open drain output, asserted when charging current is detected.
10, 11
DP_IN, DM_IN
I/O
USB 2.0 data connection to system USB connector (DM = D-, DP = D+)
12
OUT
13
FAULT
O
Active low open drain output, asserted when overcurrent, overtemperature
or reverse voltage are detected.
14
GND
-
Ground
15
NC
-
Not connected
16
ILIM
I
Current limit threshold programming resistor terminal.
PWR Device and USB port power supply input
USB 2.0 data connection to system USB transmitter (DM = D-, DP = D+)
PWR USB port power supply output (VBUS)
DocID024711 Rev 6
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32
Absolute maximum ratings and operating conditions
3
STCC2540
Absolute maximum ratings and operating conditions
Stressing the device beyond the rating listed in Table 2: Absolute maximum ratings (AMR)
may cause permanent damage to the device. These are stress ratings only and functional
operation of the device at these or any other conditions beyond those indicated in Table 3:
Operating conditions is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
Table 2. Absolute maximum ratings (AMR)
Symbol
Parameter
Value
VIN, VOUT
Supply voltage
-0.3 to 6.5
VEN, VCTLx
Logical input voltage
-0.3 to 6.5
VFAULT, VCHARGING
Pull-up voltage (FAULT, CHARGING)
-0.3 to 6.5
VDP_OUT, VDM_OUT,
VDP_IN, VDM_IN
Data switch pin voltage to ground
IO(FAULT), IO(CHARGING)
Maximum power switch output current, power switch ON
V
-0.3 to VIN +0.3
IDP_OUT, IDM_OUT, IDP_IN,
Data switch current, switch ON
IDM_IN
IO(OUT)
Unit
±50
mA
Internally limited
-
25
mA
Logical output sink current
TSTG
Storage temperature (VIN OFF)
TSLD
Lead solder temperature for 10 seconds temperature
(VIN OFF)(1)
260
Rthja
Thermal resistance junction-to-ambient VFQFPN 16L(2)
60
°C/W
-40 to TSTOP
°C
Tj
VESD(OUT, DP_IN, DM_IN)
VESD
Maximum junction temperature (internally limited)
-55 to +150
IEC61000-4-2 contact discharge
(OUT, DP_IN, DM_IN pins)
8
JEDEC human body model (all pins)(3)
2
JEDEC machine model (all pins)
200
°C
kV
V
1. Reflow at temperature of 255 to 260 °C for time < 30 seconds (total thermal budget not to exceed
180 °C for a period from 90 to 150 seconds).
2. Rth are typical values, given when mounted on a 4-layer PCB with vias.
3. Measured in recommended application circuit with 1 μF ceramic capacitor + 150 μF low ESR electrolytic capacitor
connected between OUT and GND pins (see Figure 4: Typical application diagram).
Table 3. Operating conditions
Symbol
6/32
Parameter
Value
Unit
V
VIN
Supply voltage
4.5 to 5.5
TA
Ambient operating temperature
-40 to +85
TJ
Junction operating temperature
-40 to +125
DocID024711 Rev 6
°C
STCC2540
4
Electrical characteristics
Electrical characteristics
Table 4. Electrical characteristics VIN = 4.5 to 5.5 V, -40 °C < TJ < 125 °C
(unless otherwise specified)
Symbol
Parameter
Conditions
Min. Typ. Max.
Unit
Current consumption
IACTIVE
IDISABLED
Mode CDP (111)
110
160
Mode SDP (110 - 010)
100
150
260
110
290
180
Mode DCP BC1.2 (100)
110
180
Mode DCP divider (101)
210
290
EN = 0, TJ = 25 °C
0.2
5
Mode DCP auto-detect (001)
Supply current in active state
– Divider mode
(EN = 1)
– BC1.2
Supply current in disable
state
TJ = 125 °C
µA
60
Power switch - DC parameters
RON
│IREVERSE│
VREVERSE
IOS
TJ = 25 °C
Static on-resistance
65
-40 °C < TJ < 125 °C
Reverse leakage current in
disabled state (absolute
value)
Reverse voltage protection
threshold (VOUT - VIN)
Current limiter threshold
TSTOP
Thermal shutdown threshold
THYST
Thermal shutdown
hysteresis
95
VOUT = 5.5 V,
VIN = 0, VEN = 0, TJ = 25 °C,
measured at IN
1
5
µA
TJ = 125 °C, other conditions
the same as above
70
VUVLO < VIN < VOUT, EN = 1,
power switch ON -> OFF
60
RILIM = 96 kΩ
340
RILIM = 33 kΩ
1290 1450 1595
RILIM = 19.6 kΩ
2255 2450 2645
RILIM = 17.2 kΩ
2800
140
500
mV
150
625
EN input leakage current
VEN
Enable input turn-on, turn-off
threshold voltage
VHYST(EN)
Enable input turn-on, turn-off
voltage hysteresis
VOL(FAULT)
FAULT output low voltage
VIN = 5.5 V, VEN = 0 V or 5 V
°C
-1
1
µA
0.4
1.6
V
500
IFAULT = 1 mA
DocID024711 Rev 6
mA
160
20
IEN
mΩ
mV
180
7/32
32
Electrical characteristics
STCC2540
Table 4. Electrical characteristics VIN = 4.5 to 5.5 V, -40 °C < TJ < 125 °C
(unless otherwise specified) (continued)
Symbol
Parameter
Conditions
FAULT output leakage
current
VIN = 5.5 V, VFAULT = 5 V
tFAULT
FAULT output deglitch delay
FAULT assertion / deassertion
delay in overcurrent condition
VUVLO
Undervoltage lockout
VIN rising
VHYST(UVLO)
Undervoltage lockout
hysteresis
TJ = 25 °C
IOL(FAULT)
Min. Typ. Max.
Unit
1
µA
7
9
12
ms
3.9
4.1
4.3
V
100
mV
Power switch - AC parameters(1)
tON
Turn on, EN to OUT delay
tOFF
Turn off, EN to OUT delay
tR
OUT (VBUS) rise time
tF
OUT (VBUS) fall time
tIOS
0.8
CLOAD = 1 µF, RLOAD = 100 Ω
0.3
CLOAD = 1 µF, RLOAD = 100 Ω
Current limiter response
time to short-circuit
ms
0.4
0.2
VIN = 5.5 V
3.5
µs
Output discharge
RDISCHARGE
Discharge resistor
140
200
300
4
Ω
High-speed data switch - DC parameters
Data switch on-resistance
Switch closed, VIN = 5 V,
IS = 8 mA, test voltage on
DP_OUT, DM_OUT = 0.4 V
2.5
RON
Data switch on-resistance
Switch closed, VIN = 5 V,
IS = 8 mA, test voltage on
DP_OUT, DM_OUT = 3 V
2.7
IOFF
OFF state leakage current
VEN = 0 V, VDP/DM_IN = 3.6 V,
VDP/DM_OUT = 0 V, measure
IDP/DM_OUT
RON
Ω
4
1.5
µA
High-speed data switch - AC parameters(1)
XTALK
OIRR
Bw
DP, DM crosstalk
RTERM = 50 Ω, CLOAD = 5 pF,
VS = 1 Vrms, signal = 0 dBm,
f = 250 MHz
47
OFF state isolation
RTERM = 50 Ω, CLOAD = 5 pF,
VS = 1 Vrms, signal = 0 dBm,
f = 250 MHz
17
Bandwidth -3 dB
RTERM = 50 Ω, CLOAD = 5 pF,
signal = 0 dBm
1100
CTLx configured for DCP
BC1.2
100
dB
MHz
Charger emulator - BC1.2 DCP mode
RDCP_RES
8/32
DP_IN to DM_IN short
resistance
DocID024711 Rev 6
170
Ω
STCC2540
Electrical characteristics
Table 4. Electrical characteristics VIN = 4.5 to 5.5 V, -40 °C < TJ < 125 °C
(unless otherwise specified) (continued)
Symbol
Parameter
Conditions
Min. Typ. Max.
Unit
Charger emulator - divider mode
VDM
DM_IN output voltage
Device set to DCP auto-detect
mode or divider mode,
VIN = 5.0 V
VDP
DP_IN output voltage
RDM
DM_IN output resistance
RDP
DP_IN output resistance
1.96
2
2.04
V
2.65
2.7
2.75
27
Device set to DCP auto-detect
mode or divider mode
kΩ
27
Charger emulator - BC1.2 CDP mode
VDM_SRC
Voltage source on DM_IN for VDP_IN = 0.6 V, device in CDP
CDP detection
BC1.2 mode
VDAT_REF
DP_IN rising voltage
threshold to turn on
VDM_SRC
VDAT_REF_HYST
VDAT_REF hysteresis
VLGC_SRC
DP_IN rising voltage
threshold to turn off
VDM_SRC
VLGC_SRC_HYST
VLGC_SRC hysteresis
IDP_SINK
0.5
0.6
0.7
V
0.25 0.32
0.4
30
IDM_IN = -250 µA, device in
CDP BC1.2 mode
0.8
mV
1
30
0.4 < VDP_IN < 0.8 V, device in
CDP BC1.2 mode
DP_IN sink current
50
75
V
mV
150
µA
Charger emulator - timings
tCHG_DGL_ON
Charging indication ON
deglitch delay
From IOUT > IOUT _TH to
CHARGING asserted
0.5
tCHG_DGL_OFF
Charging indication OFF
deglitch delay
From IOUT < IOUT_TH to
CHARGING deasserted
5
tVDM_SRC_ON
DM_IN voltage source turnon time
From VDP_IN 0 V -> 0.6 V to
VDM_IN = VDM_SRC, CTLx
configured for CDP BC1.2
8
tVDM_SRC_OFF
DM_IN voltage source turnoff time
From VDP_IN 0.6 V -> 0 V to
VDM_IN = 0 V, CTLx configured
for CDP BC1.2
tVBUS_REAPP
OUT discharge pulse width
From VOUT falls to 0.7 V during
discharge to VOUT returning to
90%.
DocID024711 Rev 6
s
ms
1.3
300
350
400
9/32
32
Electrical characteristics
STCC2540
Table 4. Electrical characteristics VIN = 4.5 to 5.5 V, -40 °C < TJ < 125 °C
(unless otherwise specified) (continued)
Symbol
Parameter
Conditions
Min. Typ. Max.
Unit
Charger emulator - control pins CTLx
VCTLx
CTLx pins threshold voltage
VHYST(CTLx)
Hysteresis voltage on CTLx
pins
Leakage current
ICTLx
0.4
1.6
V
500
VIN = 5.5 V, VCTLx = 0 V or 5 V
mV
-1
1
µA
Charger emulator - charging indication
Output current threshold for
charging detection
DCP mode, CDP mode
VOL(CHARGING)
CHARGING output low
voltage
Charging detected
(IOUT > IOUT_TH),
ICHARGING = 1 mA
IOL(CHARGING)
CHARGING output leakage
current
VIN = 5.5 V, VCHARGING = 5 V
IOUT_TH
20
mA
180
mV
1
µA
1. Guaranteed by design. Not tested in production.
Figure 3. Timing waveforms
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DocID024711 Rev 6
STCC2540
5
Application information
Application information
The STCC2540 device is designed to be implemented into the PC on a USB port in order to
emulate the wall charger adapter when the PC is in standby mode or OFF, and to allow
higher charge current when the USB interface is used for data communication. In order to
handle these functionalities, the STCC2540 device relies on USB BC1.2 specifications,
Chinese telecommunications industry standard YD/T 1591-2009, and proprietary
implementations.
•
•
BC1.2 charging profiles are
–
CDP: charging downstream port providing data communication plus charging
(active USB data communications with 1.5 A support)
–
SDP: standard downstream port providing data communication with no charging
(active USB 3.0 data communications with 900 mA support or USB 2.0 data
communications with 500 mA support)
–
DCP: dedicated charging port (wall charger emulation with no data communication
and 500 mA to 1.5 A support)
Chinese telecommunications standard
–
D+ and D- shorted to allow charging
•
Apple divider mode (2 A max. current)
•
BlackBerry emulator mode
•
Legacy mode (allowing 500 mA charging current)
•
Korean tablet charging mode (D+ and D- shorted and pulled up to a certain voltage)
Figure 4. Typical application diagram
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DocID024711 Rev 6
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32
Application information
5.1
STCC2540
Supported modes
For more information refer to Section 5.4: State machine.
The STCC2540 device supports the following modes:
•
SDP BC1.2
•
CDP BC1.2
•
SDP with remote wakeup for all USB devices
•
CDP with remote wakeup for low-speed USB devices with automatic transition to DCP
auto mode if a full-speed/high-speed USB device attached or after a USB device
detached.
•
DCP auto-detect: this mode permits auto-detection of charging modes between DCP
BC1.2 (shorted D+, D-) and divider charging mode. It also supports BlackBerry
charging mode and can charge legacy devices and Korean tablets.
•
Forced DCP BC1.2 mode
•
Forced DCP divider mode
The auto-detect mode starts in divider mode. If charging negotiation attempt is detected,
there is an automatic transition to DCP BC1.2 mode. It is preceded by VBUS discharge pulse
to initialize the proper BC1.2 handshake process. If the BC1.2 device is detached, the circuit
automatically returns to divider mode after a 10 s (typ.) timeout.
Note:
From an application point of view it means that after removing one device the user should
wait for approx. 15 s before attaching another device.
Selection between these modes is done through the CTLx control pins. The CTLx pins may
be controlled by the host in different ways:
•
GPIO from embedded controller
•
Hardware signals from USB host controller (SLP_S3#, SLP_S4#) and AC_adapter
signal from embedded controller
•
Hardware signals SUSPEND from embedded controller and AC_ADAPTER.
Table 5. Truth table control pins CTLx(1)
Host state
CTL1
CTL2 CTL3
Mode description
0
0
0
Device off, output discharge
S0, S1,
(S3)(2)
1
1
0
SDP
S0, S1,
(S3)(2)
1
1
1
CDP BC1.2 with charging detection.
(2)
0
1
0
SDP with remote wakeup for all USB devices
S3
0
1
1
CDP with remote wakeup for low-speed USB devices / DCP auto mode for
full-speed or high-speed USB devices or after a USB device detached.
S4, S5
0
0
1
DCP auto-detect mode without remote wakeup, with charging detection
S4, S5
1
0
1
Forced DCP divider mode with charging detection
S4, S5
1
0
0
Forced DCP BC1.2 mode with charging detection
S3, (S0, S1)
1. On the transition from the CTLx = 111 to CTLx = 001, a synchronous transition of the CTL1 and CTL2 must be ensured.
2. See Section 5.2 for further information.
12/32
DocID024711 Rev 6
STCC2540
5.2
Application information
Remote wakeup in S3
For more information refer to Section 5.4: State machine.
If the CTLx pins are controlled by hardware signals (such as SLP_Sx# or SUSPEND), the
CTLx combination changes when host transitions from S0 to S3 and back. In this case, the
STCC2540 device can support remote wakeup of portable devices for the following
transitions (i.e. no VBUS discharge pulse and data switch ON):
•
SDP S0 (CTLx = 110) to and from SDP S3 (CTLx = 010) for all USB devices
•
SDP (CTLx = x10) and CDP S0 (CTLx = 111) to and from CDP S3 (CLx = 011) for lowspeed USB devices only.
If the host system is in S3 mode (CTLx = 011), the system automatically turns into DCP auto
mode for already attached full-speed / high-speed USB devices or after any USB device is
detached. Thus, already attached full-speed / high-speed devices or newly attached devices
are charged without the need of CTLx transition.
If the S0 to S3 transition is managed by GPIO from the embedded controller, the easiest
solution is to keep the same levels on the CTLx pins (SDP or CDP modes). Therefore,
remote wakeup in S3 is supported for all USB devices but the system does not
automatically turn into DCP auto mode.
5.3
VBUS discharge
The VBUS discharge pulse lasts for 350 ms typ. (tVBUS_REAPP) and is performed for any
transitions between the modes listed in Table 5, except the modes allowing remote wakeup
in S3 [transitions (x10) and (111) to/from (011)] (see Section 5.4).
Permanent output discharge is provided in following modes:
•
EN = 0, CTLx = xxx (ignored)
•
EN = 1, CTLx = 000.
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Application information
5.4
STCC2540
State machine
Figure 5. State machine
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STCC2540
5.5
Application information
Charging detection
The STCC2540 device continuously monitors the current drawn by the portable device.
While programmed in CDP or DCP mode, the STCC2540 device sends a charging flag to
the system if the current through the USB power switch is above the charging threshold, set
at 20 mA typ.: open drain active low output CHARGING is asserted.
Note:
In CDP mode, the charging flag is asserted only if the CDP handshaking between the
portable device and the host is performed before the current is above the threshold.
If a device is charging (CDP mode) while the system is turned off and the battery supplied,
the risk is that the charging process stops before the end of charge due to the system
power-off. To avoid this, the flag CHARGING can be used by the host to prevent the
switching-off of the high power DC-DC converter when the host goes to S5 state, even if
battery supplied.
After the charging current drops below the threshold and the deglitch delay expires, the
CHARGING output is deasserted.
5.6
Power switch
Overcurrent conditions
When an overcurrent condition is detected, the device maintains a constant output current
and reduces the voltage accordingly. There are two overload conditions:
•
The first occurs when a short-circuit or a partial short-circuit is already present when
the device is being powered-up or enabled. The output voltage is held near zero
potential with respect to ground and the STCC2540 device ramps the output current to
IOS until the overload condition is removed or the device starts thermal cycle.
•
The second condition is when a short-circuit, a partial short-circuit, or a transient
overload occurs while the device is already enabled and powered-on. The STCC2540
device responds to an overcurrent condition within time tIOS. The current-sense
amplifier is overdriven during this time and momentarily disables the internal current
limit MOSFET. It then recovers and ramps the output current to IOS. Similar to previous
conditions, it limits output current to IOS until the overload condition is removed or
thermal cycle starts.
Thermal protection
The STCC2540 device has an internal thermal sensing circuit which monitors the operating
temperature of the circuit. It disables the power switch operation if the die temperature
exceeds temperature threshold TSTOP, set at 150 °C. The switch turns on if the temperature
has cooled down by 20 °C.
Undervoltage lockout
The UVLO circuit disables the circuit until the input voltage reaches the UVLO turn-on
threshold. Built-in hysteresis prevents unwanted on/off cycling due to input voltage drop
during turn-on.
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Application information
STCC2540
FAULT functionality
The FAULT open drain active low output is asserted during overcurrent or overtemperature
conditions. Signal is asserted until the fault is removed.
For overcurrent conditions, the STCC2540 device is designed to eliminate false FAULT
reporting, by using an internal deglitch delay (9 ms typ.).
In the case of overtemperature, there is no deglitch delay and the FAULT signal is asserted
immediately. It is deasserted with a delay after the device has cooled down and begins to
turn on. This unidirectional glitch immunity prevents FAULT oscillation during an
overtemperature event.
In the case of a fault condition, the host may disable the power switch by toggling EN input
to logic low.
Current limit programming
The current limit can be adjusted by an external resistor in the range 500 mA to 2.8 A
(max.). The programming resistor may be calculated using these equations:
Equation 1
48000
I OS ( typ ) = ---------------- ( mA, kΩ)
R ILIM
Equation 2
48000
I OS ( min ) = ------------------------- ( mA, kΩ)
1.037
R ILIM
Equation 3
48000
I OS ( max ) = ------------------------- ( mA, kΩ)
0.962
R ILIM
Equation 2 and Equation 3 allow the minimum and maximum variation to be estimated
around the typical value predefined by the external resistor, RILIM, given in Equation 1.
Equation 2 and Equation 3 do not take into consideration external resistor variations.
5.7
Enable input
The enable input (EN, active high) serves to turn off the STCC2540 device and achieve the
lowest current consumption.
The behavior of the STCC2540 in disabled state (EN = 0) is following:
16/32
•
Power switch, USB data switch and emulation profiles are turned off
•
Output discharge circuit is turned on
•
The FAULT and CHARGING flags are cleared (the FAULT and CHARGING outputs are
set to Hi-Z mode).
DocID024711 Rev 6
STCC2540
5.8
Application information
Input and output capacitors
For proper functionality, the STCC2540 device requires two 1 μF decoupling ceramic
capacitors CIN and COUT (see Figure 4). These capacitors should be placed as close as
possible to the corresponding pins.
The electrolytic capacitor CVBUS (see Figure 4) is required by the USB specification to
suppress the voltage and current transients caused by hot plugging/unplugging the
peripheral devices. This capacitor should be placed as close as possible to the USB
connector. The recommended value is 150 μF, low ESR type is preferred.
If the VIN supply path is longer than approx. 150 mm, an additional capacitor is required and
should be connected in parallel with the CIN to suppress VIN overvoltage transients caused
by supply path inductance and fast current changes. The minimum value is 10 μF, and a low
ESR type is preferred.
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Typical operating characteristics
6
STCC2540
Typical operating characteristics
Figure 6. Power switch ON resistance vs. temperature
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Figure 7. OUT discharge resistance vs. temperature
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STCC2540
Typical operating characteristics
Figure 8. OUT short-circuit current limit vs. temperature (RILIM = 96 kΩ)
,26 >P$@
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$0
Figure 9. OUT short-circuit current limit vs. temperature (RILIM = 33 kΩ)
,26 >P$@
-XQFWLRQWHPS HUDWXUH>Σ&@
$0
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Typical operating characteristics
STCC2540
Figure 10. OUT short-circuit current limit vs. temperature (RILIM = 19.6 kΩ)
,26 >P$@
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Figure 11. Disabled IN supply current vs. temperature
,,1',6$%/(' > $@
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$0
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STCC2540
Typical operating characteristics
Figure 12. Enabled IN supply current vs. temperature (SDP mode)
,,1$&7,9(6'3 > $@
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Figure 13. Enabled IN supply current vs. temperature (CDP mode)
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Typical operating characteristics
STCC2540
Figure 14. Enabled IN supply current vs. temperature (DCP auto-mode)
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Figure 15. Enabled IN supply current vs. temperature (DCP BC1.2 mode)
,,1$&7,9('&3%& > $@
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STCC2540
Typical operating characteristics
Figure 16. Enabled IN supply current vs. temperature (DCP divider mode)
,,1$&7,9('&3GLYLGHU > $@
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$0
Figure 17. Data switch transfer characteristics vs. frequency
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Typical operating characteristics
STCC2540
Figure 18. Eye diagram using USB compliance test pattern - without STCC2540
(deskew line + cable)
Figure 19. Eye diagram using USB compliance test pattern - with STCC2540 (STCC2540 + cable)
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STCC2540
Typical operating characteristics
Figure 20. Turn-on response (RILIM = 20 kΩ, RLOAD = 5 Ω, CLOAD = 150 µF)
Figure 21. Turn-off response (RLOAD = 5 Ω, CLOAD = 150 µF)
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Typical operating characteristics
STCC2540
Figure 22. Device enabled into short-circuit (RILIM = 80.6 kΩ)
Figure 23. Device enabled into short-circuit - thermal cycling (RILIM = 20 kΩ)
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STCC2540
Typical operating characteristics
Figure 24. Short-circuit to full load recovery (RILIM = 20 kΩ, RLOAD = 5 Ω, CLOAD = 150 µF)
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Package information
7
STCC2540
Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK is an ST trademark.
Figure 25. VFQFPN 16L 3 x 3 x 0.8 mm with exposed pad 1.7 package outline
9)4)31/
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STCC2540
Package information
Table 6. VFQFPN 16L 3 x 3 x 0.8 mm with exposed pad 1.7 package mechanical
data(1), (2), (3), (4)
Dimensions
Symbol
Data book (mm)
Notes
Nom.
Min.
Max.
A
0.75
0.70
0.80
A1
0.02
0
0.05
A3
0.20
b
0.25
0.18
0.30
D
3
2.90
3.10
D2
1.70
1.50
1.80
E
3
2.90
3.10
E2
1.70
1.50
1.80
e
0.50
L
0.40
0.30
0.50
(5)
1. VFQFPN - standard for “thermally enhanced very thin fine pitch quad flat package no leads”.
2. The lead size is comprehensive of the thickness of the lead finishing material.
3. Dimensions do not include mold protrusion, not to exceed 0.15 mm.
4. Package outline exclusive of metal burr dimensions.
5. The value of “L”, a JEDEC norm, is min. 0.35 – max. 0.45.
Figure 26. VFQFPN 16L 3 x 3 x 0.8 mm with exposed pad 1.7 footprint recommended
$0
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32
Ordering information
8
STCC2540
Ordering information
Table 7. Order codes
30/32
Order code
Temperature
range
Marking
Package
Packaging
STCC2540IQTR
-40 to 85 °C
2540CC
VFQFPN 16L
Tape and reel
DocID024711 Rev 6
STCC2540
9
Revision history
Revision history
Table 8. Document revision history
Date
Revision
29-May-2013
1
Initial release.
2
Updated Features on page 1 (added “CB” components).
Updated Section 1: Functional description (replaced
1000 MHz by 1100 MHz).
Updated Table 2 (added note 3.).
Updated Table 4 (updated parameters and conditions for
│IREVERSE│, IEN, IOL(FAULT), ICTLx, IOL(CHARGING), added
typ. value for XTALK, OIRR, and Bw, removed tPD and tSK
symbols).
Added Figure 4 on page 11.
Added Note: in Section 5.1: Supported modes.
Added Section 5.8: Input and output capacitors.
Added Section 6: Typical operating characteristics.
06-Dec-2013
3
Updated Table 4 (updated min. conditions for IOS RILIM 96 kΩ and RILIM 33 kΩ).
Updated Table 5 (updated Host state column, added
footnote 1. and 2.below table).
Updated Section 5.7 (replaced equation by Equation 1 to
Equation 3).
Minor modifications throughout document.
06-Jan-2014
4
Corrected units in Table 4 on page 7 (replaced “W” by “Ω
“ in RDISCHARGE, RON and RDCP_RES symbols).
5
Updated Section : Features on page 1 (removed “2.5 A”
from “Integrated VBUS power switch with low RON of 65
mΩ“ replaced “2.5 A” by “2.8 A (max.)” in “Adjustable
current limit”) .
Added List of figures on page 3.
Updated Section 1: Functional description on page 3
[replaced “2.5 A” by “2.8 A (max.)”].
Updated Table 4 on page 7 (added “RILIM = 17.2 kΩ“ and
typ. conditions of “RILIM = 17.2 kΩ“ for IOS symbol).
Updated Section : Current limit programming on page 16
[replaced “2.5 A (typ.)” by “2.8 A (max.)”].
6
Removed List of figures on page 3
Section 5.6: Power switch: updated Equation 2 and
Equation 3 and added explanation of same.
Table 7: Order codes: updated “marking” of
STCC2540IQTR
24-Jun-2013
08-Jan-2014
25-Feb-2014
Changes
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32
STCC2540
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